Rotary motor and production method thereof, and laminated core and production method thereof

ABSTRACT

An object of the present invention is to provide a low cost, high performance, thin structure rotary motor for driving medium used in magnetic disk drive unit, optical disk drive unit or the like, in order to improve the productivity of terminating processing and the reliability of the coils. Magnetic materials which are divided to a plurality of blocks or divided corresponding to respective magnetic pole teeth are connected by means of thin portions. The respective magnetic pole teeth are wound continuously with wire without cutting the wire at the positions in which the thin portions are connected. When a stator is assembled, a plurality of blocks or magnetic pole teeth are disposed on a substrate by separating or bending the thin portions.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of application Ser. No. 09/275,904 filedMar. 24, 1999, now U.S. Pat. No. 6,121,711, issued Sep. 19, 2000; whichis a division of application Ser. No. 08/582,595 filed Jan. 3, 1996, nowU.S. Pat. No. 6,167,610, issued Jan. 2, 2001; which is a division ofapplication Ser. No. 08/333,142 filed Nov. 11, 1994, now U.S. Pat. No.5,859,486, issued Jan. 12, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the construction of a thin structuremotor for driving a medium used in a magnetic disk drive unit or anoptical disk drive unit, the production method thereof, and thelaminated core and the production method thereof.

2. Description of the Prior Art

FIG. 139 shows the stator of the spindle motor for the disk drive unitdisclosed in Japanese Patent Publication No. 5-39020. The same Figureshows a stator core 20 formed integratedly by punching the magneticmaterial and stator coils 2 which are wound around respective teeth ofthe stator core 20 so that they are contained in respective slots. Thespindle motor using this stator core 20 is called inner rotor type.Inside the stator, a rotor and rotor magnets are disposed so as to facethe stator. The structure of the inner rotor makes it possible to form athin structure motor and therefore is suitable for a magnetic disk driveunit and optical disk drive unit which are required to be of compact andthin structure.

FIGS. 140, 141 show a stator of the spindle motor for the disk driveunit disclosed in Japanese Patent Laid-Open No. 2-133055 and themagnetic pole tooth of the stator core, respectively. FIG. 140 shows thestator core formed integratedly by punching magnetic material and FIG.141 shows a magnetic tooth 15 of the stator core, which is wound withstator coil 2. The spindle motor using this stator core is called outerrotor type. Outside the stator, a ring like rotor and rotor magnets aredisposed so as to face the stator. A rotor shaft is located in thecenter of the stator and the rotor shaft is connected to the ring likerotor magnet through a thin circular plate. The spindle motor havingsuch structure also makes it possible to obtain small diameter and thinstructure, and therefore is often used as the spindle motor for drivinga magnetic disk drive unit or an optical disk drive unit.

FIGS. 142A, 142B, 143A, 143B show part of the stator cores of otherspindle motors for the disk drive unit disclosed in Japanese PatentLaid-Open No. 2-133055. The spindle motor using this stator core is alsoof outer rotor type. A difference thereof from the aforementioned outerrotor structure is that part of the respective magnetic teeth can beseparated. In the stator core shown in FIGS. 142A, 142B, slot heads 15-2are inserted into the magnetic teeth wound with the coil 2. In thestator core shown in FIGS. 143A, 143B, respective magnetic teeth 15-3wound with the coils 2 are inserted into the stator body 15-1.

FIG. 146 shows the structure of a motor for the magnetic disk drive unitand optical disk drive unit disclosed in Japanese Utility ModelLaid-Open No. 5-86151. This motor is of inner rotor type. As shown inthe same Figure, three magnetic teeth constitute a stator core 20 as asingle block. Each tooth 15 is wound with the coil 2.

The feature of this motor is that the stator core 20 is not disposed inthe space in which the head of the disk drive unit moves. On thecircumference of the rotor magnet 4, in which the stator core 20 is notdisposed, shield yokes 4 a are disposed so as to cover the rotor magnet.

FIG. 147 is a partial sectional view showing the stator core and thecoil of the spindle motor of conventional floppy disk drive unitdisclosed in Japanese Patent Laid-Open No. 5- 176484. FIG. 148 is afront view of the spindle motor. This motor is of inner rotor type. Inthe respective Figures, reference numeral 122 designates a stator coreformed by punching magnetic material integratedly and numeral 130designates stator coil wound around the magnetic pole tooth 122 a of thestator core 122. The stator core 122 is formed by laminated core inwhich a plurality of magnetic materials are stacked. Resin layer isformed on the surface of the stator core 122 to insulate between thestator core 122 and the stator coil 130. Reference numeral 112designates a magnet, numeral 114 designates a shaft and numeral 116designates a yoke.

FIG. 149 shows the stator core of a conventional thin structure motordisclosed in Japanese Patent Laid-Open No. 5-38109. As shown in the sameFigure, insulating film 150 is formed on the circumference of themagnetic pole tooth of the stator core 151. That is, the insulatingsheet of thermoplastic resin is heated and pressed from both sides toform insulating film 150 on the circumference of the magnetic pole toothin order to achieve insulation treatment.

The stator shown in FIG. 139 has an integrated ring shaped stator coreand therefore, it is difficult to wind the magnetic pole teeth facinginward of the stator with stator coil. In coiling, a nozzle throughwhich wire is run is rotated around the magnetic pole teeth. However,because the inside of the stator core is small, the structure of thewinding apparatus is complicated. Additionally, the coiling speed cannotbe increased more than 1,000 rpm thereby suppressing the productivity ofcoiling low. It is impossible to increase the number of slots becausethe number of slots is restricted by the difficulty of coiling, therebyobstructing the increase of torque and resulting in torque ripple.Although winding wire of the coil neatly contributes to compacting andenhancement of the characteristic and reliability of the coil, it isimpossible to wind wire neatly because the space between the stator coreand the winding apparatus is very small.

FIG. 140 shows an integrated structure stator. Because the shape of themagnetic pole teeth of the stator core is complicated, it is impossibleto wind wire effectively. For the reason, productivity is so low thatcost increases and further a special winding apparatus is required.

Although the stator shown in FIGS. 142A, 142B was proposed to solve theaforementioned problem, it is impossible to achieve effective winding ofwire if the number of slots is increased to improve the characteristicof the motor. Further, magnetic resistance increases at portions inwhich divided stator portions are combined by engagement and air gap isunequalized, so that the characteristic of the motor deteriorates.Although winding procedure is facilitated to the stator shown in FIG.143, two coil terminals are required for every magnetic pole tooth,thereby the step for connecting coil terminals electrically aftercoiling is required. Thus, production cost is increased and thereliability of connection is decreased.

By dividing the stator core into blocks in the motor shown in FIG. 146,the difficulty of coiling which is a problem of the inner rotor type isrelaxed. However, the step for connecting the coils wound around therespective magnetic pole teeth in respective blocks after coiling isrequired, thereby increasing production cost and thus decreasing thereliability. Further, because the stator core is divided to blocks, itis difficult to fix the stator core with a certain gap with respect tothe rotor magnet. Still further, because the stator core comprisesdivided blocks, the stator core is not easy to-handle or assemble.

In the stators shown in FIGS. 147 and 148, the stator core 122 is ofintegrated ring structure. Therefore, it is difficult to wind therespective magnetic pole teeth 122 a having small gap from an magneticpole tooth nearby, with the stator coil 130 in the direction in whichthe stator coil is wound inward of the stator. Namely, when a nozzlethrough which wire is run is rotated around the magnetic pole tooth 122a for coiling, the structure of the winding apparatus is complicatedbecause the inside of the stator core is small. Additionally, it isimpossible to increase the winding speed over 1,000 rpm, therebysuppressing productivity low.

It is impossible to increase the number of slots because the number ofslots is restricted by the difficulty of coiling, thereby obstructingthe increase of torque and resulting in torque ripple. Although windingwire of the coil neatly contributes to compacting and enhancement of thecharacteristic and reliability of the coil, in this conventionalexample, it is impossible to wind wire neatly because the space betweenthe stator core 122 and the winding apparatus is very small.

Resin is integratedly molded to insulate between the stator coil 130 andthe stator core 122. In this case, because the process of integratedmolding of resin is required, production cost is increased. Further,because resin layer is formed on the stator core 122, additional lengthof the stator coil 130 is required. Thus, the amount of the magnet wireused for the stator coil 130 increases and therefore, it is impossibleto form a thin structure motor.

In the stator shown in FIG. 149, insulating film 150 is formed byheating and pressing the insulating sheet of thermoplastic resin fromboth sides of the stator core 151 in order to insulate between the coiland the stator core 151. As a result, the insulating sheet and theprocess for heating and pressing thereof are required, therebyincreasing production cost.

SUMMARY OF THE INVENTION

In views of the aforementioned problems, an object of the presentinvention is to provide a rotary motor in which it is possible to windthe stator of the rotary motor with wire easily and in which it ispossible to perform terminating and connecting treatments of the coilseasily. Another object of the present invention is to provide a rotarymotor in which the stator core can be assembled at high precision easilyto ensure high productivity and reliability at low cost.

Still another object of the present invention is to provide a rotarymotor which facilitates winding wire of the coil and which can beassembled easily having high reliability. A further object of thepresent invention is to provide a rotary motor in which the stator canbe handled separately from other members, the stator can be installed ona complicated structure base and which can be built in arecording/reproducing apparatus easily.

A still further object of the present invention is to provide alaminated core which can be formed easily and in which the coil can bearranged and formed on the magnetic pole teeth easily. A yet stillfurther object of the present invention is to provide laminated corewhich can be fixed securely to the structure through screws at positionnear the thin portions and which can form a magnetic path for connectingrespective stator components. A yet still further object of the presentinvention is to provide laminated core which is capable of preventingdeformation and damage of the thin portions before the laminated core isobtained by bending the thin portions. A yet still further object of thepresent invention is to provide laminated core in which the thinportions can be bent easily even if a large number of magnetic membersare to be stacked. A yet still further object of the present inventionis to provide laminated core in which magnetic members can be positionedand held accurately to form the coils on the magnetic teeth.

A yet still further object of the present invention is to providelaminated core which is capable of securing stabilized integratedstructure so that the laminated core can be installed rigidly andsecurely. A yet still further object of the present invention is toprovide laminated core which can be wound with wire directly or throughthin film. A yet still further object of the present invention is toprovide laminated core which is capable of preventing magnet wire frombeing damaged by the corners at both ends of the magnetic materials. Ayet still further object of the present invention is to providelaminated core which can be wound with wire by only simple insulatingtreatment. A yet still further object of the present invention is toprovide laminated core in which the terminal wire of the coil to bewound around the magnetic pole teeth can be treated easily. A yet stillfurther object of the present invention is to provide laminated corewhich facilitates to construct a transformer.

A yet still further object of the present invention is to provide themethod for forming the laminated core, in which the laminated core ofthe stator can be assembled easily and quickly. A yet still furtherobject of the present invention is to provide a method for forming thelaminated core, in which the laminated core can be formed in simplerprocess.

The rotary motor according to the first aspect comprises a statorportion having coils which are disposed on respective magnetic poleteeth of the stator core formed by stacked magnetic materials and arotor portion which is disposed along the inner circumference of thestator portion. The stator portion is constituted of blocks includingthe same number of magnetic pole teeth as the number of the phases ofthe rotary motor. The stator portion is fixed on molded resin product orsubstrate so as to face the rotor portion, in the state in which aplurality of the blocks are connected through the thin portions or aplurality of the blocks are separated by cutting the thin portions.

In this rotary motor, it is easy to form the coils for each blockbecause the same number of magnetic pole teeth as that of the phases arecontained in a single block. That is, it is possible to locate a wirewinding machine at a position facing a plurality of connected blocks andfurther, the space necessary for the wire winding machine is notrestricted by the shape of the stator. Still further, because, after theformation of the coil is completed, the stator portion is mounted andfixed onto the molded resin product or substrate with the state in whichthe thin portions are connected or the thin portions are cut off, theassembly of the stator is facilitated and performed with higheraccuracy.

The rotary motor according to the second aspect of the present inventionincludes magnetic pole teeth which are parallel to each other in eachblock.

Because the magnetic pole teeth of each block are parallel to eachother, when coils are formed on respective magnetic pole teeth, thenozzle of the wire winding machine is located parallel to all themagnetic pole teeth. Thus, the construction of the wire winding machinecan be simplified. Additionally, by providing the wire winding machinewith the same number of the nozzles as the number of the magnetic poleteeth in a single block, it is possible to wind wires on a plurality ofcoils at the same time. Further, because the motion of the nozzle can besimplified when wire is wounded, it is also possible to improve thespeed of wire winding and reduce the possibility of winding faultoccurrence. According to these effects, it is possible to improve theproductivity of winding the stator with wire.

The rotary motor according to the third aspect of the present inventionincludes a coil which is disposed on the yoke portion of the block.

Because this rotary motor is provided with a coil at the yoke portion ofthe block also, as compared with the stator in which coils are disposedon only the magnetic pole teeth, it is possible to relatively increasethe amount of the coil in a limited space. Thus, the torque of therotary motor can be increased. As compared with conventional rotarymotor having the same output, the structure of the rotary motor can bethinned because the coils can be arranged with improved balance.

The rotary motor according to the fourth aspect of the present inventionincludes a block or a plurality of the blocks which have the samepotential level as the power supply terminal of the coil or the neutralpoint terminal, and uses the stator as the connecting terminal.

Because a block or a plurality of the blocks have the same potential asthe power supply terminal or the neutral point terminal of the coil, noadditional connecting terminal is needed to automatically process theterminal of the coil when the teeth are wound with wires. Additionally,a plurality of the blocks can be used as the connecting terminals at thesame time. That is, when the teeth are wounded with wires, the terminalsof the coils are directly tied and soldered to the blocks which need tobe electrically connected, so that processing of the terminals of thepower supply terminal or the neutral point terminal is facilitated.

In the rotary motor according to the fifth aspect of the presentinvention, two protrusions having a step are provided so as to beperpendicular to the substrate at a piece facing the substrate, of thecore members of the blocks, the stator being inserted into holes made onthe substrate for the positioning and fixing thereof.

In this rotary motor, it is possible to connect the block directly withthe substrate, so that a plurality of the blocks can be arranged andassembled highly accurately. That is, the deflection between the rotorand the stator can be minimized, so that a rotary motor which is hardlydeflected due to occurrence of cogging torque can be obtained.

The production method for the rotary motor according to the sixth aspectof the present invention comprises the process for punching the magneticmaterial by press so that a plurality of blocks are connected in seriesin a direction perpendicular to the direction of magnetic flux flow ofthe center magnetic pole teeth of each block, the process for stacking aplurality of the magnetic materials and the process for forming thestator by continuously winding a plurality of the magnetic pole teeth ofthe stacked magnetic materials without cutting the crossover wire.

The production method for the rotary motor according to the seventhaspect of the present invention comprises the process for mounting thestator on a molded resin product or a substrate in the state in whichthe thin portions of a plurality of the blocks are bent or the thinportions of a plurality of the blocks are separated.

According to this method, the formation of coils when wire is wound isfacilitated thereby making it possible to simplify the construction ofthe wire winding machine and increase the speed of wire winding.Further, it is possible to minimize the connecting point for treatmentof the terminal because wire is continuously wound without cutting thecrossover wire. Still further, it is possible to mount the blocks easilyat high accuracy. Thus, the productivity and the reliability can beimproved and a high power motor can be obtained at low cost.

The production method for the rotary motor according to the eighthaspect of the present invention comprises the step for forming themagnetic material having a plurality of blocks by punching by means ofpress and for forming the insulation for the magnetic pole teeth byintegrated resin molding, the fixing portions of the block and pins forholes provided on both ends or a single side of the blocks, and the stepin which the thin portions of a plurality of blocks are cut and bentwith respect to the pins formed by the integrated resin molding in orderto assemble the stator coiled with wire onto the substrate.

According to this method, the formation of coils when wire is wound isfacilitated thereby making it possible to simplify the construction ofthe wire winding machine and increase the speed of wire winding.Further, it is possible to minimize the connecting point for treatmentof the terminal because wire is continuously wound without cutting thecrossover wire. Still further, it is possible to mount the blocks easilyat the forming accuracy of integrated resin molding. Thus, theproductivity and the reliability can be improved and a high power motorcan be obtained at low cost.

The rotary motor according to the ninth aspect of the present inventioncomprises the stator portion in which the coils are disposed onrespective magnetic pole teeth of the stator core formed by stacking themagnetic materials and the rotor disposed on the inner circumference ofthe stator portion, one or a plurality of added sections being providedusing iron substrates in the portions in which part of the magnetic poletooth of the stator is cut off.

If the stator is provided with a cut-out section in which the carriageof a read/write head reciprocates in a inner rotor type medium rotationdriving motor such as a magnetic disk, the cut-out section of the statorreduces unbalanced load on the rotor shaft. Thus, it is possible toincrease the service life of the rotor bearing. Because the cut-outsection of the stator exists, attraction between the rotor magnet andthe stator becomes ununiform. However, the added section of the ironsubstrate compensates for the imbalance of the attraction. That is, theadded section substitutes the cut-out portion of the stator.

The rotary motor according to the tenth aspect of the present inventioncomprises the stator portion in which the stator core is divided tosections corresponding to the magnetic pole teeth and in which the coilsare formed on the respective magnetic pole teeth, and the rotor, thestator portion being fixed so as to face the rotor portion in the statein which the crossover wires of the coils of the magnetic pole teeth areconnected with each other.

In producing this rotary motor, the productivity of wire winding isextremely high because the stator is divided. Further, because thecrossover wires of the coils are continuously wound, the terminals ofthe coils can be processed with minimized number of steps, and connectedeasily, and the reliability is high.

According to the rotary motor according to the eleventh aspect of thepresent invention, the rotor facing surface of the magnetic pole teethmounted on a molded resin product or a substrate is cut by laser beam orthe like or shaved.

The rotary motor according to the present aspect is capable ofmaintaining a gap between the rotor facing surface of each magnetic poletooth and the rotor. This rotary motor reduces the unevenness of therotation and improves the characteristic by setting the air gap at asmall value.

In the rotary motor according to the twelfth aspect of the presentinvention, the yoke portions of the magnetic pole teeth fixed on themolded resin product or substrate are fused thermally by laser beam andfixed so that the yoke portions are fit to each other.

The rotary motor according to the present aspect enables the stator tobe mounted and fixed easily at high precision. Additionally, the rotarymotor according to the present aspect enables reduction of theunevenness of the rotation and the improvement of the characteristic ofthe motor by setting the design value of the air gap at a small value.

In the rotary motor according to the thirteenth aspect of the presentinvention, the neutral point is connected directly to the magneticmaterials of the magnetic pole teeth so that the potential of theneutral point is on the same level as that of the magnetic material.

The rotary motor according to the present aspect does not necessitateadditional connecting terminal for connecting to the neutral point.Additionally, it is possible to process the terminal of the neutralpoint at the same time when the coils are formed.

In the rotary motor according to the fourteenth aspect of the presentinvention, the rotor facing surface is formed so as to have a pluralityof steps along the length of the motor shaft or have oblique surfacewith respect to the length of the motor shaft. As a method for reducingthe cogging torque of the motor, there is a method for producingmagnetic formation on the rotor magnet in the form of a spiral. Howeverin this case, a special apparatus is required to realize the method andfurther the accuracy of magnetic formation was low.

In the rotary motor according to the fifteenth aspect of the presentinvention, magnetic material wire is wound around or in the vicinity ofthe rotor facing surface of the stator by several turns.

According to the aforementioned construction, part of magnetic fluxwhich effectively acts on the rotor magnet from the magnetic pole teethleaks to the magnetic pole teeth nearby, so that cogging torque occursinactively, thereby reducing the unevenness of the rotation.

The production method for the rotary motor according to the sixteenthaspect of the present invention comprises the process for punchingmagnetic material in the state in which a plurality of magnetic poleteeth are connected in series along the direction of magnetic flux flow,the process for continuously winding neighboring magnetic pole teethwith wire and the process in which the magnetic pole teeth are cut offby laser beam and mounted on molded resin product or substrate.

According to this method, the formation of the coils by winding wire isfacilitated, and the frequency of connection in processing the terminalsis minimized and the connecting processing can be automated.Additionally, this method enables assembling of the stators easily athigh precision, thereby improving the productivity and the reliabilityof the motor.

The production method for the rotary motor according to the seventeenthaspect of the present invention comprises the process for producing acore in which a plurality of core portions are arranged in series, theprocess for winding the respective core portions of the core with wireand the process for forming the core wound with wire by bending theportions of the core.

In the rotary motor according to the eighteenth aspect of the presentinvention, the stator core is a core which is linearly extensible andprovided with a storage container for storing and fixing the core.

In producing the rotary motor according to the present aspect, it iseasy to wind the core with wire easily, thus the rotary motor can beassembled easily.

The rotary motor according to the nineteenth aspect of the presentinvention comprises windows for inspecting the inside of the storagecontainer.

Because workers can produce this rotary motor checking the insidethrough this windows, it is possible to mount the internal components athigh accuracy.

In the rotary motor according to the twentieth aspect of the presentinvention, respective typing portions which are the coil terminatingportions of the storage container are disposed in parallel to each otherwith the same pitch as that of the magnetic pole teeth.

In producing the rotary motor according to the present aspect, the tyingportions can be wound with wire by means of the wire winding machine forwinding the coils.

The production method for the rotary motor according to the twenty firstaspect of the present invention comprises the process for winding thecoil winding portion with wire from the outer edge and the process forinserting and fixing the connected magnetic pole teeth from the outercircumference after the coils are made.

Because the tip portions of the magnetic pole teeth which are anobstacle for making the coils on the core are not provided in producingthis rotary motor, the procedure for winding with wire is easy.

According to the production method for the rotary motor according thetwenty second aspect of the present invention, the magnetic pole teethhaving the same width from the tip to the root are used in theaforementioned method.

Because the stator core according to the present aspect can be insertedinto the storage container easily, the assembly work of the rotary motoris simplified.

In the rotary motor according to the twenty third aspect of the presentinvention, the stator core is linearly extensible and provided with acircular holding ring for holding the core.

Because the core can be fixed to the holding ring easily in producingthis rotary motor, it is easy to handle the parts.

In the rotary motor according to the twenty fourth aspect of the presentinvention, the stator core is linearly extensible and comprises thestorage container for storing and fixing the core and the magneticbalancer provided in the portion in which the stator core is notprovided, the relationship between the gap gb between the magneticbalancer and the rotor, and the gap gt between the tip of the magneticpole teeth of the stator core and the rotor being gb>gt.

In this rotary motor, it is possible to reduce the deflection of therotation resulting from the influence of the portion in which the statoris not provided.

In the rotary motor according to the twenty fifth aspect of the presentinvention, the magnetic balancer is fixed in the storage container.

Because the magnetic balancer can be used as part of the stator inproducing this rotary motor, it is easy to fit the parts easily andhandle the parts easily.

In the rotary motor according to the twenty sixth aspect of the presentinvention, the stator core is linearly extensible and comprises thestorage container for storing and fixing the core, a plurality ofmagnetic pole teeth are disposed in parallel to each other in the statorcore and the diameter of the coil increases as the length thereofincreases.

This rotary motor enables to eliminate the imbalance of the magneticfield generated on respective magnetic pole teeth.

In the rotary motor according to the twenty seventh aspect of thepresent invention, the stator core is linearly extensible and comprisesthe storage container for storing and fixing the core, the magnetic poleteeth of the stator core are disposed in parallel to each other and thewire winding position differs depending on the length thereof.

This rotary motor enables to eliminate the imbalance of the magneticfield generated in respective magnetic pole teeth.

The production method for the rotary motor according to the twentyeighth aspect of the present invention comprises the process forproducing a linear core and the process in which the magnetic pole teethdisposed almost in parallel to each other on the linear core are woundedwith wire.

This method makes it possible to simplify the construction of the wirewinding machine and improve the productivity of wire winding.

In the rotary motor according to the twenty ninth aspect of the presentinvention, the stator core is linearly extensible, and comprises thestorage container for storing and fixing the core and the rotor which isconcentric with the stator core, the stator core being provided with aportion in which no block is provided, the rotor being placedeccentrically toward said portion.

Because the unbalanced magnetic attraction in this rotary motor isreduced, the torque loss is reduced.

In the rotary motor according to the thirtieth aspect of the presentinvention, the stator core is linearly extensible, and comprises thestorage container for storing and fixing the core and the rotor which isconcentric with the stator core, the stator core being provided with aportion in which no block is provided, the block gap located on theopposite side of the portion in which no block is provided being set soas to be larger than other block gap.

Because the unbalanced magnetic attraction in this rotary motor isreduced, the torque loss is reduced.

In the rotary motor according to the thirty first aspect of the presentinvention, the stator core is linearly extensible, and comprises thestorage container for storing and fixing the core and the rotor which isconcentric with the stator core, the shortest magnetic pole tooth of thestator core block being provided with the trimmed caulking portions forlaminating and fixing the stator core.

Because the difference of magnetic resistance between the respectivemagnetic pole teeth of this rotary motor is reduced, the torque rippleis reduced.

In the laminated core according to the thirty second aspect of thepresent invention, the stacked magnetic materials comprises a pluralityof core portions and the thin portions which connect these core portionsand can be bent after the materials are stacked.

It is easier to form the laminated core, and arrange and form the coilon the magnetic pole teeth of the laminated core as compared withconventional laminated core. Additionally, as compared with thelaminated core in which the coil portion is divided, the number of theparts for the laminated core can be decreased and the necessity ofhandling small parts can be eliminated. Further, because the laminatedcore can be disposed freely, the sheet materials of the magneticmaterials can be used effectively as compared with the integrated core,so that the amount of the materials to be thrown away when punching canbe reduced. Because the core portions are connected by means of the thinportions, when a plurality of the coils are wound with wires, it ispossible to continuously wind the terminal wire of the coil withoutcutting the wire between the core portions. Thus, it is possible toeliminate the procedure required for connecting work between the coils.

The laminated core according to the thirty third aspect of the presentinvention has protrusions which are formed on both sides of the thinportion by bending the thin portions so that the protrusions abut eachother, the protrusions forming a fastening member insertion portion forforming magnetic path and fixing the core when thin portions are bent soas to be attached to each other.

According to this construction, a plurality of the core portions of thelaminated core can be fixed to a construction body in the vicinity ofthe thin portions by means of screws or the like. Further, the magneticpath connecting the respective stator components can be formed easily.

The laminated core according to the thirty fourth aspect of the presentinvention is provided with reinforcing portions which reinforce the thinportions in the shape of bridge and can be arbitrarily removed.

This construction makes it possible to prevent the thin portions of thelaminated core from being deformed and damaged when the core is punchedby press. Further, this construction prevents the thin portions frombeing deformed by annealing the laminated core or treatment for coiling.Still further, the reinforcing portions can be removed easily when thethin portions are bent.

The laminated core according to the thirty fifth aspect of the presentinvention is constructed by stacking the magnetic materials in which thethin portions are formed and the magnetic materials in which no thinportions are formed.

According to this construction, the thin portions can be bent easilywhen a large number of the magnetic materials are stacked.

A laminated core according to the thirty sixth aspect of the presentinvention comprises positioning portions which are provided on both endsof the magnetic material constituted of the core portion and thinportions.

According to this construction, the laminated core can be positionedaccurately when the coils are formed on the magnetic pole teeth.

In the laminated core according to the thirty seventh aspect of thepresent invention, the protrusions on both ends of the thin portionswhich are fit to each other or placed near each other when the thinportions are bent are fused and fixed through both end faces or a singleend face.

According to this construction, the stator components (block) of thelaminated core can be connected to each other firmly.

A laminated core according to the thirty eighth aspect of the presentinvention in which a plurality of the stacked magnetic materials areintegratedly bound by spot welding at a single position or a pluralityof the positions.

According to this construction, the stacked magnetic materials areintegratedly bound at arbitrary positions with a large strength.Particularly, a plurality of the stacked magnetic materials can bestacked and fixed easily without fixing by caulking or fixing withadhesive. Additionally, because there is no obstacle against themagnetic flux passing path as compared with the case in which thetrimmed caulking portions formed by pressing are used. Still further,because the strength by spot welding is larger than that obtained bycaulking or adhesive, it is possible to select spot welding positionsfreely.

In the laminated core according to the thirty ninth aspect of thepresent invention, a plurality of the stacked magnetic materials areintegratedly bound by spot welding the protrusions on both ends of thethin portions.

According to this construction, a plurality of the stacked magneticmaterials can be integratedly fixed. Further, this construction makes itpossible to supply current through an appropriate contacting areabetween the electrode and the protrusions, thereby enhancing thestrength of binding a plurality of the magnetic materials.

In the laminated core according to the fortieth aspect of the presentinvention, dent/protruding portions are provided at a position or aplurality of positions on the front and back surfaces of the respectivestacked magnetic materials and the respective magnetic materials areengaged through the dent/protruding portions and integratedly bound byspot welding.

According to this construction, a plurality of the stacked magneticmaterials can be fixed accurately and firmly. Further, the stackedmagnetic materials can be fixed easily without fixing by caulking orfixing with adhesive. Still further, because there is no obstacleagainst the magnetic flux passing path as compared with the case inwhich the trimmed caulking portions by pressing are used, a core havingexcellent magnetic characteristics can be obtained. Still further,because the strength of projection welding is larger than that bycaulking or adhesive, it is possible to select the position of thedent/protruding portion freely.

In the laminated core according to the forty first aspect of the presentinvention, part or all of the corners of the pressed cross section of aplurality of the stacked magnetic materials have the shape of smoothroundness.

According to this construction, it is possible to wind directly thelaminated core with wire or the laminated core covered with thin coatingfilm with wire without insulation treatments on the laminated core suchas integrated molding of resin, formation of resin bobbin or fusing ofinsulating sheet.

In the laminated core according to the forty second aspect of thepresent invention, the roundness of the shape of both ends of eachstacked magnetic material is larger than that of the other corners.

According to this construction, it is possible to form the shape ofroundness as large as half of the thickness of the magnetic materialsheet at the outermost pieces of the stacked magnetic materials, so thatthe wire is not damaged even if the thickness of the magnetic materialis thin.

In the laminated core according to the forty third aspect of the presentinvention, insulating thin plates are attached to the magnetic materialson both sides of a plurality of the stacked magnetic materials.

According to this construction, insulation treatments on the laminatedcore such as integrated molding of resin, formation of resin bobbin andfusing of insulating sheet are not required before the coils are formed.Thus, winding the core with wire is facilitated.

In the laminated core according to the forty fourth aspect of thepresent invention, a wiring sheet having a wiring pattern through theinsulating material is sandwiched between two pieces of a plurality ofthe stacked magnetic materials.

According to this construction, the terminal wire of the coil which iswound around the magnetic pole teeth of the stacked core can beprocessed easily.

In the laminated core according to the forty fifth aspect of the presentinvention, a magnetic material substrate having a wiring pattern throughthe insulating material is attached to one side of a plurality of thestacked magnetic materials.

According to this construction, the terminal wire of the coil which iswound around the magnetic pole teeth of the stacked core can beprocessed easily.

In the laminated core according to the forty sixth aspect of the presentinvention, the magnetic material is bent so that the burr portions onthe edges of the magnetic material formed due to punching are on theoverlapping side and then the drooping sides are positioned on theoutside. A plurality of the pieces of such magnetic materials arestacked.

According to this construction, insulation treatments on the laminatedcore such as integrated molding of resin, formation of resin bobbin andfusing of insulating sheet are not required before the coils are formed.Thus, it is possible to wind the core directly with wire. Or it ispossible to wind the core with wire by coating the core with thincoating film.

The laminated core according to the forty seventh aspect of the presentinvention comprises the core portion which is substantially U-shapedmagnetic material to be stacked and the thin portion which is connectedto the core portion and which can be bent so as to close the U-shapedopening.

According to this construction, by closing the U-shaped opening afterthe coil is mounted, a transformer is completed. Thus, it is possible tomanufacture a transformer, a stator or the like through simplifiedprocesses.

The production method for the coil according to the forty eighth aspectof the present invention comprises the process for forming the magneticmaterial having a plurality of the core portions and the thin portionsfor connecting the core portions by punching by means of press, theprocess for forming the coils after a plurality of the magneticmaterials are stacked and the process for bending the thin portions.

According to this method, it is possible to form the coils throughsimple procedure such as bending or the like after the core is woundwith wire, thereby realizing effective production of the transformer andthe stator.

The production method for the laminated core according to the fortyninth aspect of the present invention comprises the process for bondinginsulating thin plate and conductive thin plates on the surface of themagnetic material substrate, the process for forming wiring pattern byetching the conductive material and the process for bonding the magneticmaterial substrate having wiring pattern on a single side of the stackedmagnetic materials.

According to this method, it is possible to obtain the laminated core inwhich the terminal wire of the coil can be treated easily.

The production method for the laminated core according to the fiftiethaspect of the present invention comprises the process for forming themagnetic material having a plurality of the magnetic pole teeth locatedon both sides which are opposite to each other by punching by means ofpress, the process for bending the magnetic material so that themagnetic pole teeth which are located on opposite side overlap eachother and further so that the burr portions formed by punching overlapeach other at a single position or a plurality of the positions, and theprocess for stacking the bent magnetic materials to form the laminatedcore.

Accordingly, it is possible to easily form the laminated core which canbe wound directly with the coil through simple process including bendingof the magnetic material and stacking of the layers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of the rotary motor according to the first andfifth embodiments of the present invention.

FIG. 2 is a sideways cross sectional view of the rotary rotor accordingto the first and fifth embodiments of the present invention.

FIG. 3 is a front view of the rotary motor according to the secondembodiment of the present invention.

FIG. 4 is a front view of the rotary motor according to the third andfourth embodiments of the present invention.

FIG. 5 is a partial side view of the stator according to the fourthembodiment of the present invention.

FIG. 6 is a front view of the stator core according to the first andfifth embodiments of the present invention.

FIG. 7 is a front view of the stator core being wound with wireaccording to the first, second and fifth embodiments of the presentinvention.

FIG. 8 is a front view of the stator core molded integratedly withresin, according to the sixth embodiment of the present invention.

FIG. 9 is a front view of the stator core molded integratedly withresin, according to the sixth embodiment of the present invention.

FIG. 10 is a front view of the stator and the substrate according to theseventh embodiment of the present invention.

FIG. 11 is a partial perspective view of the stator and the substrateaccording to the seventh embodiment of the present invention.

FIG. 12 is a front view of the stator according to the eighth and ninthembodiments of the present invention.

FIG. 13 is a sideways sectional view of the stator according to theeighth embodiment of the present invention.

FIG. 14 is a perspective view of the stator according to the tenthembodiment of the present invention.

FIG. 15 is a front view of the stator core according to the tenthembodiment of the present invention.

FIG. 16 is a partial side view of the stator core viewed from the rotorfacing side, according to the tenth embodiment of the present invention.

FIG. 17 is a perspective view of the stator core according to the tenthembodiment of the present invention.

FIG. 18 is a front view of the stator core according to the tenthembodiment of the present invention.

FIG. 19 is a partial sectional view of the stator core viewed from therotor facing side, according to the tenth embodiment of the presentinvention.

FIG. 20 is a front view of the stator according to the eleventhembodiment of the present invention.

FIG. 21 is a front view of the stator core according to the eighthembodiment of the present invention.

FIG. 22 is a front view of the stator core wound with wire, according tothe eighth and ninth embodiments of the present invention.

FIG. 23 is an explanatory view for explaining the procedure of wirewinding on the stator core according to the eighth embodiment of thepresent invention.

FIG. 24 is a front view of the molded resin product according to theeighth embodiment of the present invention.

FIG. 25 is an explanatory view for explaining the procedure of formingthe stator core according to the eighth embodiment of the presentinvention. FIG. 26 is a disassembly perspective view of the rotary motoraccording to the twelfth embodiment of the present invention.

FIG. 27 is a plan view of the stator core according to the twelfthembodiment of the present invention.

FIG. 28 is a sectional view of the stator core shown in FIG. 27.

S FIG. 29 is a plan view of the stator core wound with wire, accordingto the twelfth embodiment of the present invention.

FIG. 30 is a sectional view of the stator core shown in FIG. 29.

FIG. 31 is a plan view of the stator according to the twelfth embodimentof the present invention.

FIG. 32 is a plan view of the rotary motor according to the thirteenthembodiment of the present invention, in which the cover holder ispartially cut away.

FIG. 33 is a plan view of the rotary motor according to the fourteenthembodiment of the present invention, in which the cover holder ispartially cut away.

FIG. 34 is a partial sectional view of the rotary motor shown in FIG.33.

FIG. 35 is a partially enlarged view of the rotary motor shown in FIG.33.

FIG. 36 is a perspective view of the major parts of the rotary motoraccording to the fifteenth embodiment of the present invention. FIG. 37is a sectional view of the rotary motor shown in FIG. 36.

FIG. 38 is a plan view of the rotary motor according to the sixteenthembodiment of the present invention, in which the cover holder ispartially cut away.

FIG. 39 is an enlarged view of the section A shown in FIG. 38.

FIG. 40 is a plan view of the rotary motor according to the seventeenthembodiment of the present invention, in which the cover holder ispartially cut away.

FIG. 41 is a sectional view of the major parts of the rotary motor shownin FIG. 40.

FIG. 42 is a perspective view of the major parts of the rotary motoraccording to the eighteenth embodiment of the present invention.

FIG. 43 is a perspective view of the stator holder according to theeighteenth embodiment of the present invention.

FIG. 44 is an enlarged view of the stator core according to thenineteenth embodiment of the present invention.

FIG. 45 is a perspective view of the major parts of the rotary motoraccording to the twentieth embodiment of the present invention.

FIG. 46 is a plan view of the rotary motor according to the twentiethembodiment of the present invention.

FIG. 47 is a partial perspective view of the stator according to thetwenty first embodiment of the present invention.

FIG. 48 is a perspective view showing the stator according to the twentysecond embodiment of the present invention and the fixing means for theholding ring.

FIG. 49 is a perspective view of the stator according to the twentythird embodiment of the present invention and the fixing means for theholding ring.

FIG. 50 is a partially cutaway plan view of the rotary motor forexplaining the deflection of the rotation in the twenty fourthembodiment of the present invention.

FIG. 51 is a partially cutaway plan view of the rotary motor accordingto the twenty fourth embodiment of the present invention.

FIG. 52 is an explanatory diagram for showing the relationship betweenthe gap gb between the magnetic balancer and the rotor magnet in thetwenty fourth embodiment, and the deflection of the rotation.

FIG. 53 is a partially cutaway plan view of the rotary motor accordingto the twenty fifth embodiment.

FIG. 54 is a perspective view showing the fixing means for the magneticbalancer and the stator according to the twenty sixth embodiment of thepresent invention.

FIG. 55 is a perspective view showing the magnetic balancer and thestator according to the twenty seventh embodiment of the presentinvention.

FIG. 56 is a perspective view of the major parts of the rotary motoraccording to the twenty eighth embodiment of the present invention.

FIG. 57 is a plan view of the major parts of the rotary motor accordingto the twenty ninth embodiment of the present invention.

FIG. 58 is a perspective view showing the jointing means for themagnetic balancer according to the twenty ninth embodiment of thepresent invention.

FIG. 59 is a perspective view showing the jointing means for themagnetic balancer according to the thirtieth embodiment of the presentinvention.

FIG. 60 is a perspective view showing the configuration of and thejointing means for the magnetic balancer according to the thirty firstembodiment of the present invention.

FIG. 61 is an enlarged view of the stator for explaining magneticresistance or the like in the thirty second embodiment of the presentinvention.

FIG. 62 is an enlarged view of the block of the stator according to thethirty second embodiment of the present invention.

FIG. 63 is an enlarged view of the block of the stator according to thethirty third embodiment of the present invention.

FIG. 64 is an enlarged view of the block of the stator according to thethirty fourth embodiment of the present invention.

FIG. 65 is a plan view of the state in which the stator core accordingto the thirty fifth embodiment of the present invention is being coiled.

FIG. 66 is a plan view for explaining the unbalanced magnetic attractionin the thirty sixth embodiment of the present invention.

FIG. 67 is a plan view of the major parts of the rotary motor accordingto the thirty sixth embodiment of the present invention.

FIG. 68 is a plan view of the major parts of the rotary motor accordingto the thirty seventh embodiment of the present invention.

FIG. 69 is a perspective view of the major parts of the rotary motoraccording to the thirty eighth embodiment of the present invention.

FIG. 70 is a sectional view of the magnetic pole teeth of the rotarymotor shown in FIG. 69.

FIG. 71 is a disassembly perspective view showing the state in which therotary motor according to the thirty ninth embodiment of the presentinvention is mounted on an apparatus.

FIG. 72 is a front view showing the rotary motor according to thefortieth embodiment of the present invention.

FIG. 73 is a front view of the laminated core of the rotary motor shownin FIG. 72.

FIG. 74 is a side view of the laminated core shown in FIG. 73.

FIG. 75 is a front view showing the laminated core according to thefortieth embodiment of the present invention, in which the coils areformed.

FIG. 76 is a side view of the laminated core shown in FIG. 75.

FIG. 77 is a front view showing the stator according to the fortiethembodiment of the present invention, in which the thin portion of thelaminated core is deformed.

FIG. 78 is a front view showing other laminated core according to thefortieth embodiment of the present invention.

FIG. 79 is a side view of the laminated core shown in FIG. 78.

FIG. 80 is a front view showing the laminated core according to thefortieth embodiment of the present invention, in which other coils areformed.

FIG. 81 is a side view of the laminated core shown in FIG. 80.

FIG. 82 is a front view showing the stator in which the thin portions ofother laminated core are deformed, according to the fortieth embodimentof the present invention.

FIG. 83 is an explanatory view showing the state in which the coils areformed on the laminated core according to the fortieth embodiment of thepresent invention.

FIG. 84 is a plan view showing the state in which the laminated core inwhich the coils are formed according to the fortieth embodiment of thepresent invention is being bent.

FIG. 85 is a plan view showing the state in which bending of thelaminated core shown in FIG. 84 is finished.

FIG. 86 is a front view showing the state in which materials of thelaminated core according to the fortieth embodiment of the presentinvention are obtained by punching by means of press.

FIG. 87 is an explanatory view showing the state in which thereinforcing members of the laminated core shown in FIG. 86 are removed.

FIG. 88 is a front view showing further other laminated core accordingto the fortieth embodiment of the present invention.

FIG. 89 is a partial perspective view of the laminated core shown inFIG. 88.

FIG. 90 is a partial perspective view showing the state in which theprotrusions of the laminated core according to the fortieth embodimentof the present invention are fused together.

FIG. 91 is a partial side view of the fused portion shown in FIG. 90.

FIG. 92 is an explanatory view showing the state in which the laminatedcore according to the fortieth embodiment of the present invention isintegratedly fused.

FIG. 93 is a partial front view showing the protrusions for electricallyfusing the laminated core according to the fortieth embodiment of thepresent invention integratedly.

FIG. 94 is an explanatory view for explaining the state in which theprotrusions of the laminated core according to the fortieth embodimentof the present invention are electrically fused.

FIG. 95 is a partial sectional view of the laminated core which iselectrically fused, shown in FIGS. 92, 94.

FIG. 96 is a partial sectional view showing the magnetic material ofother laminated core according to the fortieth embodiment of the presentinvention.

FIG. 97 is an explanatory view showing the state in which the laminatedcore shown in FIG. 96 is electrically fused.

FIG. 98 is a partial sectional view of the laminated core which iselectrically fused, shown in FIG. 96.

FIG. 99 is a partial perspective view showing another laminated coreaccording to the fortieth embodiment of the present invention.

FIG. 100 is a partial sectional view showing still another laminatedcore according to the fortieth embodiment of the present invention.

FIG. 101 is a partial sectional view showing further laminated coreaccording to the fortieth embodiment of the present invention.

FIG. 102 is a partial sectional view showing still further laminatedcore according to the fortieth embodiment. FIG. 103 is a partialperspective view showing a yet still further laminated core according tothe fortieth embodiment of the present invention. FIG. 104 is a partialsectional view of the laminated core shown in FIG. 103.

FIG. 105 is a disassembly perspective view showing an enlargement of ayet still further laminated core according to the fortieth embodiment ofthe present invention.

FIG. 106 is a partial sectional view of the laminated core shown in FIG.105.

FIG. 107 is a disassembly perspective view of a yet still furtherlaminated core according to the fortieth embodiment of the presentinvention.

FIG. 108 is a partial sectional view of the laminated core shown in FIG.107.

FIG. 109 is an explanatory view showing the state in which the magneticmaterials are bent according to the forty first embodiment of thepresent invention.

FIG. 110 is an explanatory view showing the shape before the magneticmaterial shown in FIG. 109 is bent.

FIG. 111 is an explanatory view showing the shape after the magneticmaterial shown in FIG. 109 is bent.

FIG. 112 is an explanatory view showing the state in which the bentmagnetic materials shown in FIG. 111 are stacked.

FIG. 113 is an explanatory view showing the state in which the magneticpole tooth of the magnetic material is bent according to the forty firstembodiment of the present invention.

FIG. 114 is an explanatory view showing the state in which the magneticpole teeth shown in FIG. 113 are stacked.

FIG. 115 is a front view showing the laminated core according to theforty second embodiment of the present invention.

FIG. 116 is a front view of another laminated core according to theforty second embodiment of the present invention.

FIG. 117 is an explanatory view showing the state in which the neutralpoint treatment portion and the connector portion are integratedlymolded in the laminated core according to the forty second embodiment ofthe present invention.

FIG. 118 is a front view showing the state in which the coils are formedon the laminated core shown in FIG. 117.

FIG. 119 is a front view showing the process in which the laminated coreaccording to the forty second embodiment of the present invention isbeing wound with wire.

FIG. 120 is a front view showing the state in which the laminated coreshown in FIG. 119 is being bent.

FIG. 121 is a front view showing the rotary motor having the laminatedcore according to the forty second embodiment of the present invention.

FIG. 122 is a front view showing another rotary motor having thelaminated core according to the forty second embodiment of the presentinvention.

FIG. 123 is a front view showing still another rotary motor having thelaminated core according to the forty second embodiment of the presentinvention.

FIG. 124 is a front view showing the process in which the laminated coreaccording to the forty second embodiment of the present invention isbeing wound with wire.

FIG. 125 is a side sectional view showing a further rotary motor havingthe laminated core according to the forty second embodiment of thepresent invention.

FIG. 126 is a front view showing the laminated core according to theforty third embodiment of the present invention.

FIG. 127 is a front view showing the state in which the laminated coreshown in FIG. 126 is wound with wire to form the coil.

FIG. 128 is an explanatory view showing the state in which the laminatedcore shown in FIG. 127 is being wound with wire.

FIG. 129 is a front view showing the state in which the laminated coreshown in FIG. 127 is being bent.

FIG. 130 is a front view showing the state in which bending of thelaminated core shown in FIG. 127 has been finished.

FIG. 131 is a front view showing the rotary motor having the statorshown in FIG. 130.

FIG. 132 is a front view showing the state in which the laminated coreis being bent after the rotor shown in FIG. 129 is mounted.

FIG. 133 is a front view showing the rotary motor having the statorshown in FIG. 132.

FIG. 134 is a side sectional view showing another rotary motor havingthe laminated core according to the forty third embodiment of thepresent invention.

FIG. 135 is a front view showing the laminated core according to theforty fourth embodiment of the present invention.

FIG. 136 is a front view showing the state in which the coil is mountedto the laminated core shown in FIG. 135.

FIG. 137 is a front view showing the state in which the bobbin havingthe coil is-being mounted onto the laminated core shown in FIG. 136.

FIG. 138 is a front view showing the transformer according to the fortyfourth embodiment of the present invention.

FIG. 139 is a front view of conventional stator.

FIG. 140 is a front view of conventional stator core.

FIG. 141 is a partial enlarged view of the stator shown in FIG. 140.

FIGS. 142A, 142B are partial front views of another conventional stator.

FIGS. 143A, 143B are partial front view of another conventional stator.

FIGS. 144A, 144B are diagrams showing the result of the analysis ofmagnetic field of conventional stator.

FIGS. 145A, 145B are diagrams showing the result of the analysis ofmagnetic field of the stator according to the present invention.

FIG. 146 is a plan view of conventional rotary motor.

FIG. 147 is a partial sectional view showing a conventional stator coreand a conventional coil in the rotary motor shown in FIG. 146.

FIG. 148 is a front view of conventional inner rotor type thin structurerotary motor.

FIG. 149 is a front view of the conventional laminated core havinginsulating film.

DESCRIPT

ION OF THE PREFERRED EMBODIMENTS Embodiments of the present inventionwill be described with reference to the accompanying drawings.

Embodiment 1

A rotary motor according to the first embodiment of the presentinvention will be described with reference to FIGS. 1, 2, 6 and 7. FIG.6 shows a connecting stator core 20 which is formed by punching magneticmaterial by means of press. In the connecting stator core 20, the samenumber of magnetic teeth as the number of the phase of the motor arecomposed as a single block. A plurality of blocks of the connectingstator cores 20 are connected by means of thin portions 10. In producingthe stator, some pieces of the connecting stator cores 20 are stackedand then subjected to insulation processing by coating or the like.Next, stacked connecting stator cores 20 i.e. a laminated core is woundwith wires. That is, both ends of the stacked connecting stator cores 20are held with tension applied thereto as shown in FIG. 7 and nozzles 21of a winding machine which spouts conductive wire are turned around themagnetic teeth 15 in order to form coils. Although the magnetic poleteeth 15 of a conventional motor are arranged radially around the motorshaft, in this case, the magnetic pole teeth 15 are arranged so as to beparallel to each other in a single block as shown in FIGS. 1, 7. Aplurality of the blocks 9 are connected to each other by means of thinportions 10. In winding process, a winding machine is placed at aposition facing the connecting stator core 20 and one or a plurality ofwire winding nozzles 21 are turned around the magnetic pole teeth. Thewire winding nozzle 21 can be fed forward and backward with respect tothe magnetic pole teeth 15 upon being turned around the magnetic poleteeth thereby facilitating winding wires neatly.

Then, the thin portions 10 are bent by means of a cylindrical jig placedon the side facing a rotor to form the wound connecting stator cores 20in a desired shape of the stator.

The formed stator 1 is disposed and fixed to a molded resin housing 5 asshown in FIGS. 1, 2 by crushing stator fixing pins by ultrasonic fusingor the like. The molded resin housing 5 is fixed to a substrate 6. Inthe substrate 6, a rotor 3 is supported through a bearing.

FIGS. 144A and 144B show the result of magnetic field analysis of aconventional stator core. FIG. 144A shows the flux density at respectivelocations of the stator core. FIGS. 145A and 145B shows the result ofmagnetic field analysis of the stator core according to the presentinvention. FIG. 145A shows the flux density at respective locations ofthe stator core. As evident from FIGS. 144A and 145A, there is nodifference of the distribution of flux density between the conventionalstator core and the stator core of the present invention. Namely, in thestator core according to the present invention, magnetic flux in thepass “a” in FIG. 144B is eliminated by block division, however, it ispossible to prevent a drop of the characteristic of the motor byassuring the magnetic flux of the yoke portion sufficiently.

Embodiment 2

Then, the rotary motor according to the second embodiment will beexplained with reference to FIGS. 3, 7. In the rotary motor of thepresent invention, the coil 2 is formed around the magnetic pole teeth15 and yoke coils 17 are formed on the yoke portion 16. Thus, magneticflux generated in the coils 2 of the magnetic pole teeth 15 flows to theyoke portion 16 as well as to the rotor 3. The yoke coil 17 is suppliedwith electricity to enhance the magnetic flux flowing through the yokeportion 17.

When the yoke coil 17 is wound with wire, the stacked connecting statorcore 20 is turned around its longitudinal length and the wire windingnozzle 21 is used. In this case, a single wire winding nozzle 21 shouldbe used because the yoke coil 17 is wound with wire.

Embodiment 3

Then, the rotary motor according to the third embodiment will bedescribed with reference to FIG. 4. As in the first embodiment, thestacked connecting stator core 20 is wound with wire. However, in thiscase, the beginning end and the terminating end of the coil are tied onpart of the block. After winding of wire terminates, the tied portion issoldered to electrically connect the coil end to the stator corematerial of each block. As for the tying protrusion 34 on which wire istied, in the case of three phase, three protrusions for common terminalportion 11 are provided and three protrusions for coil terminal portion12 are provided. The three tying protrusions 34 for the common terminalportion 11 are provided on the same block 9.

When the stator is assembled, the thin portion 10 of the stator is cutwithout cutting the crossover wire 25 and the stator is installed to thesubstrate. Neutral point connection is achieved by placing three tyingprotrusions 34 at the same potential level within a single block. Thecoil terminal portion 12 is connected to the coil power supply sectionof the substrate through each block.

Embodiment 4

Next, the rotary motor according to the fourth embodiment of the presentinvention will be described with reference to FIGS. 4 and 5. In eachstacked connecting stator core 20, each respective block 9 near thesubstrate is provided with two stepped protrusions 19 which areperpendicular to the substrate 6. Insulation procedure and windingprocedure are performed in the same manner as in the first embodiment.When the stator is assembled to the substrate 6, the thin portion 10 iscut, the stepped protrusions 19 are inserted into holes provided on thesubstrate 6 to position the stator, and then the stepped protrusions 19are fixed with adhesive.

Embodiment 5

Then, the production method for the rotary motor will be described withreference to FIGS. 1, 2, 6 and 7. First, respective connecting statorcores 20 are formed by punching magnetic material by means of press. Theconnecting stator core 20 is formed so that the respective blocks 9 areconnected linearly in a direction perpendicular to the direction ofmagnetic flux flow in the central teeth. After insulation processing isperformed by coating or the like, coils are formed on respectivemagnetic pole teeth 15 so that the coils are continuous without cuttingthe crossover wire 25. Then, a bending jig is placed on the side facingthe rotor of the connecting stator core 20 and the thin portions 10 arebent. The connecting stator cores 20 are disposed and fixed to themolded resin housing 5. Fixing of the connecting stator cores 20 to themolded resin housing 5 is performed by crushing the stator fixing pinprovided on the molded resin housing 5 by ultrasonic fusing or the like.The coil terminal portions 12 are temporarily tied to part of theconnecting stator core 20 and wires are placed up to the land positionof a wiring pattern on the substrate and then connected to the land.

Embodiment 6

The production method of other rotary motor will be described withreference to FIGS. 8, 9. First, respective connecting stator cores areformed in the same manner as described above. Then, the connectingstator cores 20 are stacked, and subjected to insulation treatment andintegrated resin molding by integrally molded resin 22 in order to fixthe block. Resin pins 23 are formed on the block fixing portion. Then,coils are formed on respective magnetic pole teeth 15 so that they arecontinuous without cutting the crossover wire 25. Then, the thin portion10 of the connecting stator core 20 is cut and nearby blocks are turnedrelative to the resin pins 23 by means of a jig placed on the sidefacing the rotor in order to form a stator. The integrally molded resin22 is fixed to the substrate 6 by means of adhesive or the like.

Embodiment 7

The rotary motor according to the seventh embodiment of the presentinvention will be described with reference to FIGS. 10, 11. If thestator is provided with a cut-out section in which the carriage of aread/write head reciprocates in an inner rotor type medium rotationdriving motor such as a magnetic disk, an unbalanced load occurs.

Then, rising sections 24 are provided with the iron substrate 6 in theportion in which part of the stator is cut off. In order to compensatefor the imbalance of magnetic attraction due to the cut-off of thestator, a plurality of rising sections 24 having a large width aredisposed with an appropriate gap with respect to the rotor.

Embodiment 8

Next, the rotary motor according to the eighth embodiment of the presentinvention will be described with reference to FIGS. 12, 13 and 21-25.FIGS. 12, 13 show an outer rotor type in which the stator core isdivided for every magnetic pole tooth. As shown in FIG. 21, theconnecting stator cores 20 are produced by punching the material in theform of a plurality of magnetic pole teeth 15 which are connected in thedirection of magnetic flux of the magnetic pole teeth 15. That is, theconnecting stator core 20 is a string composed of magnetic pole teethhaving the same phase, which are connected to each other with the thinportions 10.

A plurality of stacked pieces of the connecting stator cores 20 aresubjected to insulation treatment such as coating. Then, as shown inFIG. 23, both ends of the stacked connecting stator cores 20 are pulledby means of the stator holding apparatus 32 and the connecting statorcores 20 are rotated with respect to the length thereof to wind theconnecting stator cores 20 with wires. FIG. 22 shows the connectingstator cores 20 after wound with wires. The crossover wire 25 betweenthe coils of the magnetic pole teeth is wound so as to be continuouswithout cutting the crossover wire as shown in FIG. 22.

Then, the stator is assembled. As shown in FIG. 25, a resin moldedproduct 26 shown in FIG. 24 is set on a rotary jig. The magnetic poleteeth 15 are assembled to the resin molded product 26 by cutting thethin portions 10 of the connecting stator cores 20 of different phaseswhich are wound with wires by means of laser or the like. Upon windingthe connecting stator core with wire, the connecting stator cores 20 arewound with wire loosely to assure tolerance of winding in order to keepthe crossover wire 25 continuous between the magnetic pole teeth.

It is permissible to rotate an assembled stator with respect to thecenter of the stator and cut or shave the surface thereof facing therotor by means of laser beam or the like. In this case, the surface ofthe magnetic pole tooth, facing the rotor in the punched connectingstator core 20 is provided with a processing allowance.

Further, it is permissible to fit the yoke portions 16 of the magneticpole teeth 15 and fasten the yoke portions 16 by fusing thermally bymeans of laser beam or the like after the stator is assembled. FIG. 12shows the fusion-fixed portion 27.

Embodiment 9

It is permissible to compose the rotary motor as follows. As shown inFIGS. 22, 12, the beginning end and the terminating end of the coil aretied to both ends of the connecting stator core 20. One end thereof isthe common terminal portion 11 and the other end is the coil terminalportion 12. Although the coil terminal portion 12 is separated from themagnetic pole tooth when the stator is assembled and connected onto theland of the wiring pattern, the common terminal portion 11 is directlyconnected to the stator core by soldering or the like. Becauserespective magnetic pole teeth which are divided when the stator isassembled are fit to each other or bonded with each other, the statorhas the same potential as the neutral point potential.

Embodiment 10

Then, the rotary motor according to the tenth embodiment of the presentinvention will be described with reference to FIGS. 14-19. FIG. 14 showsan example in which the rotor facing surface 28 is formed so as to havea plurality of steps along the length of the shaft of the rotary motor.This composition can be achieved by using a plurality of cores havingdifferent shapes. FIGS. 15, 16 show an example in which the magneticpole teeth are formed so as to have two steps. FIGS. 17, 18, 19 show aconstruction in which the rotor facing surface 28 of the magnetic poleteeth is partially bent to provide slanted portions 30.

It is possible to reduce the unevenness of the rotation resulting fromcogging torque easily by changing the shape of the core material of thestator. As a method for reducing the cogging torque of the rotary motor,it is possible to produce magnetic formation on the rotor magnet in theform of a spiral. However, a special apparatus is required to realizethe method and further the accuracy of magnetic formation was low.

Embodiment 11

It is permissible to construct the stator as shown in FIG. 20 to reducethe unevenness of rotation. That is, magnetic material wire 31 is woundaround or in the vicinity of the rotor facing surface of the statoraccording to the eighth embodiment by several turns.

Consequently, part of magnetic flux which effectively acts on the rotormagnet from the magnetic pole teeth leaks to the magnetic pole teethnearby, so that cogging torque occurs inactively thereby reducing theunevenness of rotation.

Embodiment 12

The rotary motor according to the twelfth embodiment will be describedwith reference to FIGS. 26-31. FIG. 26 is a disassembly perspective viewof the rotary motor. The rotary motor of the present embodiment is athin inner rotor type brushless motor which is used for a flexible diskdrive, a hard disk drive or the like. Reference numeral 1 designates thestator, numeral 3 designates the rotor, numeral 230 designates a coverholder which acts as the protective member for the rotary motor, numeral40 designates the base and numeral 50 designates a magnetic balancer.The stator 1 is formed and then fixed to the cover holder 230.

The stator 1 comprises the stacked stator core 1 a in which the statorcores 20 produced by punching magnetic material by means of press asshown in FIGS. 27, 28 are stacked, and the coils 2 which are woundaround the stacked stator core la as shown in FIGS. 29, 30. As shown inFIG. 27, the stator core 20 is formed so that a plurality of the blocks9 are connected to each other by means of the thin portions 10. Eachblock 9 is composed of the same number of the magnetic pole teeth 15 asthe number of the phases of the rotary motor. Winding of wire for thecoil 2 is performed in the state in which the stacked stator core la isplaced straightly as shown in FIG. 27. Generally, the coil 2 is formedaround the stacked stator core la after the stator core la is subjectedto insulation treatment such coating.

In the rotor 3 shown in FIG. 26, a spindle shaft 8 is held in the centerthereof and comprises a circular rotor holder 223 which acts as the backyoke of the rotor magnet 4, connecting the spindle shaft 8 to the rotormagnet 4, and a hub 224 mounted on the rotor holder 223. The base 40 hasthe bearing 7. The rotor 3 is mounted so that the bearing 7 engages withthe spindle shaft 8.

The stator 1 is formed by deforming the thin portion 10 from linearshape to circular shape. After this, the stator 1 is mounted on thecover holder 230. The stator portion 100 comprising the stator 1 and thecover holder 230 as shown in FIG. 26 is fastened to the base 40 throughscrew portions 42 provided on the base 40 and screws 60 so that therotor magnet 4 faces the tips 15 a of the magnetic pole teeth 15 with apredetermined gap therebetween. Reference numeral 43 designates aninsulating sheet which insulates the coil 2 from the base 40.

As described above, the shape of the stator 1 is determined by the coverholder 230 to hold the stator 1. Additionally, the cover holder 230protects the stator 1 and the rotor 3.

According to the present embodiment, the stator 1 which comprises aplurality of the blocks 9 is incorporated in the cover holder 230 whichacts as the protective member of the rotary motor thereby increasing theaccuracy of the location of the stator cores 20. Further, the statorportion 100 including the cover holder 230 can be handled more easily,thereby facilitating the assembly of the rotary motor. Still further,because the stator portion 100 can be handled separately, it is possibleto incorporate the rotary motor on a complicated structure base.

Embodiment 13

The twelfth embodiment shows the stator core 20 in which the blocks 9are connected to each other by means of the thin portions 10. As shownin a plan view of FIG. 32 in which part of the cover holder 230 is cutaway, it is permissible to construct the stator 1 in which the thinportions 10 are broken and the blocks 9 are incorporated within thecover holder 230 such that the blocks 9 are connected to each other. Inthis case also, the same effect can be achieved.

Embodiment 14

The rotary motor according to the fourteenth embodiment of the presentinvention will be described with reference to FIGS. 33-35. FIG. 33 is aplan view of the rotary motor in which the cover holder 230 is partiallycut away. FIG. 34 is partial sectional view of the rotary motor shown inFIG. 33 and FIG. 35 is a partially enlarged view of the rotary motorshown in FIG. 33. As shown in FIG. 33, the stator 1 is embedded in thecover holder 230 which is resin molded to a predetermined shape. Theposition of the stator core along the height thereof is determined bymaking the top face of the back yoke portion 218 in the rear of theblock 9 in contact with the abutment surface 231 provided on the coverholder 230 and further the top of the tip 15 a of the magnetic poleteeth 15 in contact with the abutment surface 232.

Further, the position of the stator core along the radius thereof isdetermined by making the rear side of the back yoke 218 in contact withthe abutment surface 233 as shown in FIG. 35. The position of the statorcore along the circumference thereof is determined by making both sidesof the tip 15 a of the magnetic pole teeth 15 in contact with thepartition portions 234 which act as the rib of the cover holder 230. Asshown in FIGS. 33, 35, the cover holder 230 has holding pins 235 at suchpositions in which the thin portions 10 of the stator core 20 areinserted. Further, supporting pins 236 are provided so as to engage withthe fixing portions 219 provided on both ends of the stator core. Then,the stator 1 is fixed to the cover holder 230 by caulking the tips ofthe supporting pins 235, 236 by means of thermal means such as a heaterchip, as sown in FIG. 34.

The supporting pins 235 have a function for pressing the stator 1against the abutment surface 233 of the cover holder 230 by itselasticity. Further, as shown in FIG. 34, the cover holder 230 isprovided with a loosening stopper portion 237 for the rotor 3 such thatthe cover holder 230 does not overlap the rotor magnet 4 interferingtherewith in terms of the height. By producing the cover holder 230 bymolding resin, it is possible to provide the cover holder with apositioning means and a fixing means easily. By using these means, it ispossible to position and fix the stator 1 to the cover holder 230easily.

According to the present embodiment, the cover holder 230 is produced bymolding resin so as to serve as a protective cover for the rotary motoralso and includes a positioning portion for positioning the stator 1 onthe cover holder 230, a fixing portion for fixing the stator 1 and theloosening stopper portion 237 for the rotor 3. Thus, it is possible toincorporate the stator 1 at high precision and fix it easily.Additionally, the cover holder 230 prevents the rotor 3 from loosening.

Embodiment 15

Then, the rotary motor according to the fifth embodiment will bedescribed with reference to FIGS. 36, 37. FIG. 36 is a perspective viewof the major parts of the rotary motor and FIG. 37 is a sectional viewof the rotary motor shown in FIG. 36. Reference numeral 130 designates acover holder formed of non-magnetic material by means of press. As shownin FIG. 36, the stator formed in a predetermined shape is mounted onthis cover holder 130. The position of the stator 1 along the heightthereof is determined by making the top surface of the back yoke portion218 in contact with a half pierce 131 which is provided on the topsurface of the cover holder 130 by punching or the like and further thetip 15 a in contact with the abutment surface 132 of the cover holder130. Further, the position of the stator 1 along the radius thereof isdetermined by making the rear side of the back yoke portion 218 incontact with the abutment surface 133 which is the outer circumferenceof the cover holder 130. Still further, the position of the stator 1along the circumference thereof is determined by nipping the back yokeportion 218 with the abutment surface 133 of the cover holder 130 andthe holding portion 134 and then the stator 1 is fixed to the coverholder 130. The reason is that the back yoke portions 218 are providedwith dent portions 218 a and the side face of the holding portion 134abuts the inner wall thereof, so that the stator 1 is fixed andpositioned to the cover holder 130. The holding portion 134 possessesalso the function for pressing the stator 1 against the abutment surface133 by means of elasticity.

Further, as shown in FIG. 37, the cover holder 130 is provided with theloosening stopper portion 135 for the rotor 3 so that the cover holder130 does not overlap the rotor magnet 4 interfering therewith in termsof the height. By producing the cover holder 130 by forming non-magneticmaterial by means of press, it is possible to provide the cover holder130 with a positioning means and a fixing means for the stator 1 easily.By these means, it is possible to position and fix the stator 1 to thecover holder 130 easily.

According to the present embodiment, the cover holder 130 is produced byforming of non-magnetic material by means of press, the cover holderalso acting as the protective cover of the rotary motor and includes thepositioning portion for positioning the stator 1 in the cover holder130, the stator holding portion 134 for nipping the back yoke portion218 connecting magnetically respective magnetic pole teeth and the rotorloosening stopper portion 135. Thus, it is possible to incorporate thestator 1 in the cover holder 130 at high precision and fix the stator 1thereto easily. Additionally, it is possible to prevent the rotor 3 frombeing loosed by means of the cover holder 130.

Embodiment 16

Then, the rotary motor according to the sixteenth embodiment will bedescribed with reference to FIGS. 38, 39. FIG. 38 is a plan view of therotary motor in which part of the cover holder 230 is cut away. FIG. 39is an enlarged view of the section A of the rotary motor shown in FIG.38. In the rotary motor, the cover holder 230 in which the stator 1 isfixed has several windows which allow to see the tips 15 a of themagnetic pole teeth 15 and the rotor magnet 4 from above. Thus, it ispossible to observe the gap gt between the tip 15 a and the rotor magnet4 by means of a video camera or the like. As a result, by developingimages of the output of the video camera or the like and observing theresult of the developed images, an operator can adjust the statorportion 100 through the respective windows 238 so as to equalize the gapgt. Thus, it is possible to dispose the stator portion 100 at highprecision with respect to the rotor 3.

Embodiment 17

The rotary motor according to the seventeenth embodiment of the presentinvention will be described with reference to FIGS. 40, 41. FIG. 40 is aplan view of the rotary motor in which part of the cover holder 230 iscut away. FIG. 41 is a sectional view of the major parts of the rotarymotor shown in FIG. 40. Reference numeral 239 designates a coilterminating portion provided on the cover holder 230 and tying portions239 a corresponding to the number of phases of the rotary motor areprovided at the tips of the coil terminating portions. The terminal 2 tof the coil 2 is tied up to the tying portion 239 a. In this manner, theterminal 2 t of the coil 2 is not an obstacle when the stator portion100 is handled. Additionally, by arranging the tying portions 239 a inparallel to each other with the same pitch as that of the magnetic poleteeth 15, it is possible to wind the tying portion 239 a with theterminal 2 t of the coil 2 using the same winding machine as the windingmachine for winding the stacked stator core 1 a. Further, by providingthe coil terminating portion 239 on the same level as the substrate 6 asshown in FIG. 41, soldering of the terminal 2 t of the coil 2 wound onthe tying portion 239 a to the substrate 6 is facilitated thereby makingit easy to automate the soldering process. In the same Figure, numeral271 designates an insulating layer for insulating the substrate 6 fromthe coil 2 and numeral 272 designates solder.

As described above, because the cover holder 230 is provided with theterminating portion 239 of the coil 2, the coil terminal 2 t is not anobstacle when the stator portion including the cover holder 230 ishandled. Additionally, soldering work of the coil terminal 2 t issimplified.

Embodiment 18

The rotary motor according to the eighteenth embodiment of the presentinvention will be described with reference to FIGS. 42, 43. FIG. 42 is adisassembly perspective view of the major parts of the rotary motor.FIG. 43 is a perspective view of the stator holder 80. As shown in FIG.43, the stator holder 80 comprises coil winding portions 81 providedsubstantially radially, holding ring portion 82 which connects the coilwinding portions 81 along the inner circumference thereof, and statorinsertion portions 83 which are through holes provided substantiallyradially from the coil winding portion 81 to the holding ring portion82. The coil winding portion 81 is wound with the coil 2 from the outeredge. As shown in FIG. 42, the stacked stator cores 1 a are insertedinto the stator insertion portions 83 of the stator holder 80 in thedirection indicated by the arrow B from the outer circumference and thenthe stacked stator cores la are positioned by making the back yokeportion 218 in contact with the coil winding portion 81. Winding of thecoil 2 is performed in the direction indicated by the arrow B. Thestator portion 100 is composed of the stator holder 80, the coil 2 andthe stacked stator cores 1 a and the rotary motor is constituted bydisposing the rotor 3 along the inner circumference thereof. Thisconstruction makes it possible to wind the coil 2 from the outercircumference in the inner rotor type rotary motor as well as in theouter rotor type rotary motor.

According to the present embodiment, the blocked stator cores 1 a areinserted into the stator holder 80 having the coil winding portions 81substantially radially provided, around which the coil 2 is wound fromthe outer circumference. Thus, the magnetic pole teeth tips (stator coreprotrusion) 15 a which act as an obstacle when the coil 2 is wound arenot provided, thereby facilitating winding process.

Embodiment 19

The rotary motor according to the nineteenth embodiment of the presentinvention will be described with reference to FIGS. 43, 44. FIG. 44 is aplan view of the stacked stator core 1 a. As shown in FIG. 44, the widthW of the magnetic pole tooth 15 of the stacked stator core 1 a is equalfrom the tip 15 a to the root of the back yoke portion 218.Consequently, insertion of the stacked stator cores 1 a into the statorholder 80 is facilitated and further the rotary motor can be assembledmore easily.

Embodiment 20

Next, the rotary motor according to the twentieth embodiment of thepresent invention will be described with reference to FIGS. 45, 46. FIG.45 is a perspective view of the major parts of the rotary motor and FIG.46 is a plan view of the major parts of the rotary motor. The stator 1in which the coils 2 are formed on the stacked stator core 1 a is bentat the thin portions 10 to be formed to a predetermined shape. Afterthis, the stator 1 is fixed onto the holding ring 90 which is ofsubstantially ring shape and which is provided so as to overlap the backyoke portion 218. The stator 1 and the holding ring 90 constitute thestator portion 100 and the rotor 3 is disposed on the innercircumference of the stator portion 100. As a result, the stator 1 inwhich the blocks 9 are connected to each other by means of the thinportions 10 can be supported stably at high precision by means of theholding ring 90.

Because the blocked stator core 1 a is fixed to the holding ring 90according to the present invention, it is possible to hold the statorcore 1 a accurately, thereby facilitating the handling of the statorportion 100 including the holding ring 90.

Embodiment 21

Although the aforementioned embodiment presents such an example in whichthe stator 1 is composed of respective blocks which are connected toeach other by means of the thin portions 10, it is permissible to havesuch a construction in which respective divided blocks 9 are mounted onthe holding ring 90 shown in FIG. 47, thereby achieving the same effectas in the aforementioned embodiment.

Embodiment 22

Next, the rotary motor according to the twenty second embodiment will bedescribed with reference to FIGS. 46, 48. FIG. 48 is a partialperspective view of the rotary motor shown in FIG. 46 for explaining thestator 1 and the holding ring 90 which is a fixing means. Referencenumeral 201 designates an electrode of a spot welding machine. The spotwelding machine 201 holds welding portions 9 a provided on both ends ofthe block 9 and welding portion 91 of the holding ring 90 between thetwo members of the spot welding machine 201, and welds the weldingportion 9 a to the welding portion 91 in order to fix the stator 1 tothe holding ring 90. The reason why the welding portion 9 a is providednot in the center of the block 9 but on the ends of the block 9 is toprevent the magnetic characteristic of the center portion of the block 9which is composed of the magnetic pole teeth 15 and the back yokeportion 218, the block forming a magnetic path, from being deterioratedby welding heat. Consequently, it is possible to fix the stator 1 to theholding ring 90 by spot welding the stator 1 to the holding ring 90.

Embodiment 23

Although the spot welding machine is used as a means for fixing thestator 1 to the holding ring 90 in the aforementioned embodiment, it ispossible to weld the welding portions 9 a provided on both ends of theblock 9 of the stator 1 to the welding portion 91 of the holding ring 90by means of YAG laser 202 as shown in FIG. 49. YAG laser is capable ofwelding more accurately than the spot welding because the stator 1 isnot pressed by the electrode 201. Additionally, because YAG laser iscapable of narrowing the range which is heated by welding although therange differs slightly depending on welding condition, magneticdeterioration of the block 9 is lower than when in spot welding.

According to the twenty-second and the twenty-third embodiments, theholding ring 90 is magnetic material and the stator core 1 a is weldedto the holding ring 90 by spot welding or laser beam. Thus, it ispossible to fix the stator core 1 a to the holding ring 90.

Embodiment 24

The rotary motor according to the twenty fourth embodiment will bedescribed with reference to FIGS. 26, 42, 46, 50, 51 and 52. Themagnetic balancer 50 shown in FIGS. 26, 42, 46 is disposed in theportion in which no block 9 of the stator 1 is provided. The magneticbalancer 50 is a magnetic field stabilizing member presenting asubstantially arc shape concentric with the rotor 3. The portion inwhich no block 9 is provided is disposed as a space in which the head ofa recording/reproducing apparatus moves. The operation of the magneticbalancer 50 will be explained according to FIGS. 50, 51. If the stator 1has the portion 1 b in which no block 9 is provided as shown in FIG. 50,magnetic field formed by the rotor magnet 4 of the rotor 3 and thestator 1 is uncontinuous at the portion 1 b, so that ripples occur inthe rotation of the rotor 3. Thus, the magnetic balancer 50 ofsubstantially arc shape is disposed in the portion 1 b as shown in FIG.51 to make magnetic field continuous, thereby reducing the ripples.

FIG. 52 shows the measurement result of the effect of the magneticbalancer 50. For this measurement, the rotor 3 having the outer diameterD of about 35 mm is used and the gap gt between the tip 15 a of themagnetic pole teeth 15 of the stator 1 and the rotor magnet 4 of therotor 3 is 0.25 mm. FIG. 52 shows the measurement result of thedeflection of the rotation when the gap gb between the magnetic balancer50 and the rotor magnet 4 is changed. Meanwhile, the deflection of therotation when no magnetic balancer 50 is provided is about 1.3%. It iswhen gb is 0.55 mm which is about twice gt that the deflection of therotation is minimized when the magnetic balancer 50 of substantially arcshape is used. The deflection of rotation increases if gb becomessmaller than gt. Thus, it is preferable to keep the relationship ofgb≧gt. If there is no problem concerned with the space, it is preferableto keep the relationship of gb ≧2×gt. As described above, it is possibleto minimize the deflection of the rotation by disposing the magneticbalancer 50 in the portion 1 b.

According to the present embodiment, the portion 1 b in which no blockis disposed is provided in part of the stator core, and the magneticbalancer 50 made of substantially arc shaped magnetic material isprovided so as to be almost concentric with the rotor 3, in the portion1 b. The relationship between the gap gb between the magnetic balancer50 and the rotor 3 and the gt between the tip 15 a of the electrodeteeth and the rotor 3 is set to be gb≧gt, thereby reducing thedeflection of the rotation due to the influence of the portion 1 b.

Embodiment 25

Then, the rotary motor according to the twenty fifth embodiment will bedescribed with reference to FIG. 53. FIG. 53 is a plan view of therotary motor in which part of the cover holder 230 is cut away. Themagnetic balancer 50 disposed in the portion 1 b of the stator 1 isfixed by adhesive to the balancer mounting portion 230 a of the coverholder 230 so that the magnetic balancer 50 faces the rotor magnet 4provided on the rotor 3. The cover holder 230 is provided with abalancer pressing portion 230 b in order to prevent the magneticbalancer 50 from contacting the rotor magnet 4 even if the magneticbalancer 50 is peeled. This balancer pressing portion 230 b is also aguide member for mounting the magnetic balancer 50 to the cover holder230. The magnetic balancer 50 is mounted from downward of the coverholder 230, and the position thereof is determined by the balancermounting portion 230 a, the balancer pressing portion 230 b and the topface of the cover holder. By providing the cover holder 230 with amounting portion, it is possible to mount the magnetic balancer 50easily. Further, by providing the cover holder 230 with the magneticbalancer 50, the magnetic balancer can be handled as part of the statorportion 100. Thus, the necessity of handling miscellaneous parts uponassembly of the rotary motor is eliminated thereby improvingproductivity and facilitating automation of the production.

Because the magnetic balancer 50 is fixed to the cover holder 230according to the present embodiment, it is possible to handle themagnetic balancer 50 as part of the stator so that the other parts canbe fixed and handled more easily. By providing the cover holder 230 witha magnetic balancer mounting portion, it is possible to fix the magneticbalancer to the stator portion easily.

Embodiment 26

The rotary motor according to the twenty sixth embodiment will bedescribed with reference to FIG. 54. FIG. 54 is a partial perspectiveview of the mounting portion of the magnetic balancer 50. As shown inthe same Figure, the balancer holding portions 1 c are provided on bothends of the stator 1 fixed to the holding ring 90. By spot welding thewelding portion 50 a of the magnetic balancer 50 to the balancer holdingportion 1 c, it is possible to fix the magnetic balancer 50 to thestator 1 easily. Reference numeral 201 designates the electrode of thespot welding machine. Meanwhile, it is possible to spot weld the stator1, the holding ring 90 and the magnetic balancer 50 simultaneously.

Embodiment 27

Although spot welding is used as a means for fixing the magneticbalancer 50 to the stator 1 in the aforementioned embodiment, it ispossible to weld the welding portion 50 a of the magnetic balancer 50 tothe balancer holding portion 1 c by means of YAG laser 202 shown in FIG.55.

According to the twenty-sixth and the twenty-seventh embodiments, themagnetic balancer 50 is welded to the stator core by spot welding orlaser beam. Thus, it is possible to fix the magnetic balancer 50 to thestator portion easily.

Embodiment 28

The rotary motor according to the twenty eighth embodiment will bedescribed with reference to FIG. 56. FIG. 56 is a perspective view ofthe major parts of the rotary motor. In this motor, the magneticbalancer 50 is integratedly mounted on the holding ring 90 for holdingthe stator 1. As a result, it is possible to provide the magneticbalancer 50 without increasing the number of parts. In the presentembodiment also, it is preferable that the relationship between the gapgt between the rotor magnet 4 and the tip 15 a of the magnetic poleteeth 15 and the gap gb between the rotor magnet 4 and the magneticbalancer 50 is gb≧gt as in the twenty fourth embodiment.

According to the present embodiment, when the portion 1 b in which noblock is provided is disposed in part of the stator core, the magneticbalancer 50 made of magnetic material having a substantially fan shapeconcentric with the rotor 3 is provided in the portion 1b integratedlywith the holding ring 90. Then, by maintaining the relationship betweenthe gap gb between the magnetic balancer 50 and the rotor portion andthe gap gt between the tip 15 a of the magnetic pole teeth and the rotorportion 3 so as to be gb≧gt, it is possible to suppress the deflectionof the rotation due to the influence of the portion 1 b. Additionally,it is possible to provide the magnetic balancer easily withoutincreasing the number of parts.

Embodiment 29

Next, the rotary motor according to the twenty ninth embodiment will bedescribed with reference to FIG. 57. Reference numeral 20 a designates amagnetic balancer portion concentric with the rotor 3, the magneticbalancer portion extending from both ends of the stator core 20 providedon the portion 1 b of the stator 1. The magnetic balancer portions 20 aare constructed so that they abut each other at the abutment portion 20b in the center thereof as shown in FIG. 57. As described in thesixteenth embodiment, for example, the stator cores 20 are obtained bypunching magnetic material linearly by means of press and stacked. Afterthe coils 2 are formed on the laminated stator core 1 a, the thinportions 10 of each block 9 are bent to obtain the configuration shownin FIG. 57. As described above, according to the present embodiment, itis possible to provide the stator core with the magnetic balancerportion 20 a as part of the stator core, while maintaining ease ofwinding when the coil 2 is formed.

According to the present embodiment, when the portion 1 b in which noblock is provided is disposed in part of the stator core, as themagnetic balancer 50 extending from both ends of the portion 1 b of thestator core 20 is provided, minimizing deflection of the rotation due tothe influence of the portion 1 b in which no block is achieved.

Then, jointing of the magnetic balancer portions 20 a will be describedwith reference to FIG. 58. Although, in the same Figure, respectiveblocks 9 are not connected by means of the thin portions 10 but fixed tothe holding ring 90, the method for jointing the magnetic balancerportions 20 a is the same as in the case in which the respective blocks9 are connected by means of the thin portions 10. When the magneticbalancer portions 20 a are jointed with each other, first, the magneticbalancer portions 20 a are brought into contact with each other andthen, the abutment portion 20 b is held between the electrodes 201 ofthe spot welding machine and welded together. Consequently, according tothe present embodiment, it is possible to weld the magnetic balancerportions 20 a easily and further improve the strength of the statorportion 100 by welding.

Embodiment 30

Although the aforementioned embodiment indicates the case in which spotwelding is used for jointing together the magnetic balancer portions 20a, it is possible to weld the abutment portion 20 b of the magneticbalancer portion 20 a by means of YAG laser 202 as shown in FIG. 59.

Embodiment 31

Although the abutment portions 20 b of the magnetic balancer 20 a havingflat end faces are shown in the twenty ninth and thirtieth embodiments,it is possible to increase the strength of jointing by overlapping therespective abutment portions alternately as shown in FIG. 60.

Embodiment 32

Next, the rotary motor according to the thirty second embodiment will bedescribed with reference to FIGS. 61 and 62. FIG. 61 is an enlarged viewof the block 9 of the stator 1 used in the rotary motor according to thetwelfth embodiment. When respective teeth 15 b, 15 c are provided sothat they are substantially parallel to each other as shown in FIG. 61,the lengths Lb, La of the magnetic pole teeth 15 b, 15 c from the tip 15a to the back yoke portion 218 has the relationship of Lb>La. Thus, themagnetic resistances of the magnetic paths formed in the magnetic poleteeth 15 b, 15 c are different from each other.

To verify this phenomenon, the rotor 3 is rotated by external force andvoltages induced in respective coils 2 b, 2 c were measured. Assumingthat the induced voltages of the coil 2 b, 2 c are Vb, Vc, respectively,the relationship of Vb>Vc is obtained. As a result of measurement underthe same condition as in the twenty fourth embodiment, Vc/Vb becameabout 0.98. It is well known that the induced voltage is proportional todriving force (accurately speaking, torque constant). Thus, torquesgenerated in the respective magnetic pole teeth 15 b, 15 c differ fromeach other. The difference of torque results in torque ripples.

Then, the relationship between the winding number Nc of the coil 2 c andthe winding number Nb of the coil 2 b is set so as to be Nc>Nb and d2>d1is determined so that the resistances of respective coils 2 b, 2 c arenot different, where the diameter of the coil 2 b is d1 and the diameterof the coil 2 c is d2. As a result, it is possible to equalize thetorques generated in the respective magnetic pole teeth 15 b, 15 c,thereby realizing a rotary motor having small torque ripple.

According to the present embodiment, in respective block 9 of theblocked stator core, the number of winding of the coil 2 and thediameter of the coil are increased as the length of the magnetic poleteeth 15 in the longitudinal direction thereof (magnetic path direction)is increased. Consequently, it is possible to reduce the imbalance ofmagnetic field (rotating magnetic field) among respective magnetic poleteeth 15 of the block 9, thereby minimizing torque ripple.

Embodiment 33

Then, the rotary motor according to the thirty third embodiment will bedescribed with reference to FIGS. 61, 62. In the aforementionedembodiment, the torque ripple caused from the difference between thelengths La, Lb of the magnetic pole teeth 15 b, 15 c was improved byproviding the coils with different numbers of winding. In the presentembodiment, if the width of the magnetic pole teeth 15 b is w1 and thewidth of the magnetic pole teeth 15 c is w2 as shown in FIG. 63, therelationship of w2>w1 is maintained and further d2>d1 is maintained notto make the resistances of the coils 15 b, 15 c different from eachother, where the diameter of the coil 2 b is d1 and the diameter of thecoil 2 c is d2. As a result, as in the aforementioned embodiment, it ispossible to equalize the torque generated in the respective magneticpole teeth 15 b, 15 c, thereby realizing a rotary motor having smalltorque ripple.

According to the present embodiment, in respective block 9 of a blockedstator core, the width of the magnetic pole teeth 15 and the diameter ofthe coil are increased as the length of the magnetic pole teeth 15 inthe longitudinal direction (magnetic path direction) is increased. As aresult, it is possible to reduce the imbalance of magnetic field(rotating magnetic field) generated among respective magnetic pole teeth15, thereby minimizing torque ripple.

Embodiment 34

The rotary motor according to the thirty fourth embodiment will bedescribed with reference to FIG. 64. Although the specification of wirewinding of the coil 2 has been modified to reduce torque rippleaccording to the thirty second embodiment and the thirty thirdembodiment, if the specification of the coil 2 differs between themagnetic pole teeth 15 b and 15 c, the efficiency of wire winding workdrops.

However, it is possible to cope with torque ripple by setting the wirewinding position on the respective coil 2, at a predetermined position(distance L from the tip 15 a) from the tip 15 a of the magnetic poleteeth 15 b, 15 c. In this case, the number of windings of respectivecoil 2 is the same and the diameter of the coil 2 is the same. Accordingto the present embodiment, torque ripple can be reduced without makingthe specification of wire winding of the coil 2 different between therespective magnetic pole teeth 15 b and 15 c. Thus, the efficiency ofwire winding work does not drop.

According to the present embodiment, the wire winding positions at thecoils 2 are made different depending on the length of the magnetic poleteeth 15 (magnetic path direction) in the respective block 9 of theblocked stator core. As a result, it is possible to reduce the imbalanceof magnetic field (rotating magnetic field) generated in the magneticpole teeth 15 of the block 9, thereby reducing torque ripple.

Embodiment 35

The rotary motor according to the thirty fifth embodiment will bedescribed with reference to FIG. 65. FIG. 65 is a plan view showing thestate in which the coil 2 is being formed on the laminated stator core 1a used in the twelfth, fourteenth, eighteenth, thirty second, thirtythird and thirty fourth embodiments. By positioning the respectivemagnetic pole teeth 15 of the block 9 substantially parallel to eachother as shown in FIG. 65, the nozzle 21 of the wire winding machine 203is parallel to the magnetic pole teeth 15. Thus, it is possible to formthe coil 2 on a plurality of the magnetic pole teeth 15 of the sameblock thereby improving the efficiency of wire winding. Meanwhile, bybending the thin portions 10 after the coils 2 are formed, as describedin the twelfth embodiment, the laminated stator core 1 a is formed asshown in FIG. 31.

According to the present embodiment, because the respective magneticpole teeth 15 of the block 9 are substantially parallel to each other,the nozzles 21 of the wire winding machine are placed parallel to allthe magnetic pole teeth 15 when the coils 2 are formed on the magneticpole teeth 15. Thus, it is possible to simplify the construction of thewire winding machine. Additionally, by placing the same number of thenozzles of the wire winding machine as the number of the magnetic poleteeth of a single block 9 along the magnetic pole teeth, it is possibleto form a plurality of the coils at the same time. Further, because themotion of the nozzles 21 when wire is being wound can be simplified, itis possible to improve the speed of wire winding and reduce thepossibility of fault occurrence. Accordingly, these effects make itpossible to improve the productivity of wire winding on the stator.

Embodiment 36

The rotary motor according to the thirty sixth embodiment will bedescribed with reference to FIGS. 66, 67. FIGS. 66, 67 are plan views ofthe motor. Assuming the condition in which the portion 1 b in which noblock is provided is disposed in the stator 1 as shown in FIG. 66 andthe gap g between the tip 15 a of the magnetic pole teeth 15 and therotor magnet 4 is constant, unbalanced magnetic attraction acts againstthe rotor 3 from the portion 1 b in the direction toward the spindleshaft 8 (direction X indicated by the arrow). As a result, friction onthe bearing including the spindle shaft 8 supporting the rotor 3increases. Consequently, the torque loss of the rotary motor increasesthereby reducing the motor efficiency.

Then, as shown in FIG. 67, the rotor 3 is mounted eccentrically so thatthe relationship between the gap g1 provided near the portion 1 b inwhich no block is provided and the gap g2 provided on the opposite sidethereof is g2>g1. As a result, the magnetic flux Bg1 on the side of theportion 1 b can be equivalently the same as the magnetic flux Bg2generated on the opposite side. Thus, the unbalanced magnetic attractionis reduced thereby decreasing torque loss. This reason is thatunbalanced magnetic attraction is generated due to the imbalance ofmagnetic flux in the gap and proportional to the square of the magneticflux Bg in the gap.

According to the present embodiment, the portion 1 b in which no blockis provided is disposed in part of the stator core and then the rotor 3is placed eccentrically toward the portion 1 b. As a result, theunbalanced magnetic attraction is reduced so that the load applied tothe bearing can be reduced thereby suppressing the increase of shaftloss.

Embodiment 37

The rotary motor according to the thirty seventh embodiment will bedescribed with reference to FIG. 68. In the aforementioned embodiment,the rotor 3 is mounted eccentrically toward the side of the portion 1 bin order to reduce the unbalanced magnetic attraction. However, byenlarging the gap gd of the block 9 r provided on the opposite side ofthe portion 1 b by gd relative to the other gaps g, the same effect canbe achieved.

According to the present embodiment, when the portion 1 b in which noblock is provided is disposed in part of the stator core, the gap of theblock on the opposite side of the portion 1 b is enlarged as comparedwith the gaps of the other blocks. As a result, the unbalanced magneticattraction is reduced so that the load applied to the bearing can bereduced, thereby suppressing the increase of shaft loss.

Embodiment 38

The rotary motor according to the thirty eighth embodiment will bedescribed with reference to FIGS. 69, 70. FIG. 69 is a partialperspective view of the stator portion 100 and FIG. 70 is a sectionalview of the magnetic pole tooth 15 b in the center, in which the lengthL from the tip 15 a to the root of the back yoke portion 218 is theshortest of the magnetic pole teeth 15 b, 15 c. As explained in thethirty second embodiment, if the magnetic pole teeth 15 b, 15 c areprovided substantially parallel to each other, the magnetic resistanceof the magnetic path formed in the magnetic pole teeth 15 b, 15 cdiffers, so that the magnetic resistance of the magnetic path passingthe magnetic pole tooth having a shorter L is reduced.

In this case, the magnetic pole teeth 15 b are provided with trimmedcaulking portions 20 c for stacking the stator cores 20 to fix thestator cores 20. As a result, it is possible to equalize magneticresistance of the magnetic path passing the respective teeth 15 b, 15 cby laminating the stator core by means of the trimmed caulking portionsin the magnetic pole teeth 15 b. The trimmed caulking portions 20 capply stress to the magnetic pole teeth 15 b thereby deteriorating themagnetic characteristic of the magnetic pole teeth 15 b. By providingshorter magnetic pole teeth with trimmed caulking portions, it ispossible to equalize magnetic resistance thereby reducing torque ripple.

According to the present embodiment, the magnetic pole teeth 15 b havingthe shortest length in the longitudinal direction (magnetic pathdirection) of the magnetic pole teeth 15 in the respective blocks 9 ofthe blocked stator core, with the trimmed caulking portions 20 c forlaminating and fixing the stator core, the difference of magneticresistance among the respective magnetic pole teeth decreases, so thatthe imbalance of magnetic field generated among the magnetic pole teeth15 is reduced thereby minimizing torque ripple.

Embodiment 39

In the twelfth embodiment, the stator portion 100 and the rotor 3 areattached to the base 40. However, the following construction is alsoavailable; that is, as shown in FIG. 71, the bearing 7 is provided onthe frame 140 of a flexible disk drive unit, the spindle shaft 8 of therotor 3 is engaged with the bearing 7, and then the stator portion 100incorporating the stator 1 in the cover holder 230 in a desiredconfiguration is fixed to the frame 140 through the screw 60 and thescrew portion 141. According to this construction, the bottom face ofthe cover holder 230 is in contact with the surface of the screw portion141 in order to determine the positions of the rotor 3 and the stator 1along the height thereof. However, it is preferable to set the bottomface of the laminated stator core 1 a so as to be in contact with themounting face of the frame 140 in order to enhance the accuracy ofpositioning. As described above, the stator 1 is contained in the coverholder 230 so that the stator 1 can be handled as a unit of the statorportion 100. As a result, it is possible to mount the stator 1 on aframe having complicated configuration with side wall or the like, sothat the process for building in the rotary motor is facilitated.

Embodiment 40

The rotary motor according to the fortieth embodiment will be describedwith reference to the Figure. FIG. 72 is a front view of the rotarymotor. This motor is a brushless motor having thin structure, which isused in floppy disk drive units, hard disk drive units or the like.Reference numeral 1 designates a stator, numeral 2 designates coilswound around the magnetic pole teeth 15 of the stator 1, numeral 3designates a rotor, and numeral 4 designates a rotor magnet. The stator1 is constructed so that a plurality of stator components (block) 9 areconnected by means of the thin portions 10. Each respective statorcomponent 9 comprises a plurality of magnetic pole teeth 15.

FIG. 73 is a front view of the laminated core (laminated connectingstator cores) constituting the stator 1 shown in FIG. 72. FIG. 74 is aside view thereof. As shown in Figures, the shape of the magneticmaterial 321 obtained by punching by means of press, that is, the shapeof the stator core, is changed to a shape different from the stator 1shown in FIG. 72 with respect to a plurality of the stator components 9and the thin portions 10 which connect the stator components. Referencenumeral 20 designates the laminated core if required.

Thin magnetic material 321 obtained by punching by means of pressextends straight, and on the other hand, the shape of the stator 1 iscircular. A plurality of the magnetic materials 321 or the connectingstator cores are stacked to form the laminated core 20. Referencenumeral 311 designates a pair of protrusions extending on both sides ofthe thin portion 10.

FIG. 75 is a front view showing the state in which the coils 2 areformed around the magnetic pole teeth 15 of the laminated core 20. FIG.76 is a side view thereof. When the coils 2 are formed, as shown in FIG.83, for example, the wire winding machine 203 is located at a positionfacing the laminated core 20 formed straight. Then, a wire or wires areintroduced from a wire winding nozzle or a plurality of wire windingnozzles respectively, and a wire or wires are wound around the magneticpole tooth or teeth 15.

In this condition, the wire winding machine 203 can be located withoutbeing restricted by the shape of the laminated core 20, and thereforethe coils 2 can be formed easily, so that it is possible to wind wiresneatly, quickly and at high density. Additionally, when the coils 2 areformed on a plurality of the stator components 9, it is possible to windwires continuously without cutting the wires between the statorcomponents 9 to secure the crossover wire 25 at the thin portion 10,when the coils 2 are formed on a plurality of the stator components 9,thereby simplifying the procedure for connecting wire between the coils2.

FIG. 77 is a front view showing the stator 1 which is deformed to acircular shape by bending the thin portions 10 after the coils 2 areformed on the laminated core 20. FIG. 84 shows a process in which thethin portions 10 are being deformed with the stator 1 being pressed onthe bending jig 319.

FIG. 85 shows the state in which the stator 1 having an appropriateshape has been obtained by bending the thin portions 10. As comparedwith the stator in which the laminated cores 20 are independent, thisconstruction does not increase the number of the parts of the laminatedcore 20 and eliminates the necessity of handling small parts.

FIG. 78 is a front view showing the laminated core 20 of the othershape. FIG. 79 is a side view of the laminated core 20 shown in FIG. 78.Different from the laminated core shown in FIG. 73, the laminated core20 of the present embodiment is provided with respective protrusionswhich act as a magnetic path forming portion 314 which is formed on bothsides of the thin portion 10. FIG. 80 shows the state in which the coils2 are formed on the laminated core 20 shown in FIG. 78. FIG. 81 is aside view of the laminated core shown in FIG. 78. FIG. 82 shows thestator 1 which is deformed to a circular shape by bending the thinportion 10 as in FIG. 77.

When the circular shaped stator 1 is formed, a magnetic path is formedby the respective pairs of the magnetic path forming portions 314located on both sides of the thin portions 10 as shown in FIG. 82. Bythe respective pairs of protrusions 311 located on both sides of thethin portion 10 as shown in FIG. 77 and the magnetic path formingportion 314 located on both sides of the thin portions 10 as shown inFIG. 82, fastening member insertion portions such as C-shaped cut-outportions 10 a and circular holes 10 b into which resin pins, screws orthe like are to be inserted or screwed to fasten the stator 1 onto thesubstrate or the like are formed. The fastening member insertionportions are capable of fixing a plurality of the stator components 9 ofthe laminated core 20 tightly on both sides thereof.

FIG. 86 shows magnetic material 321 of the other shape, obtained bypunching by mean of press. The magnetic material 321 has bridge-likereinforcing portions 309 in the vicinity of the thin portions 10. FIG.87 shows the state in which the reinforcing portions 209 for reinforcingthe thin portions 10 are removed after the coils 2 (not shown) areformed.

This procedure makes it possible to prevent the thin portions 10 of thelaminated core 20 from being deformed or damaged in annealing thelaminated core 20 or treatment for coiling. By placing the magneticmaterial 321 to be punched by means of press as shown in FIG. 86 in thepress punching process, the sheets of the magnetic material can be usedmore effectively than in the case of the integrated type core, therebyreducing the amount of the material to be thrown away by punching.

FIG. 88 is a side view of the laminated core 20 in which the connectingstator cores punched by means of press so as to form the thin portion 10as shown in FIG. 73 are combined with the magnetic material in which nothin portion is formed. FIG. 89 is a partial perspective view of thelaminated stator core 20 which is deformed to the shape of the stator 1.Here, thin portion missing portion 329 is formed. This constructionmakes it possible to bend the thin portion 10 easily even if a number ofthe magnetic materials are stacked in the laminated core 20.

The connecting stator core shown in FIG. 73 has fixing portions 219 onboth sides thereof. The fixing portion 219 may be a positioning portionmade of a hole, circular shaped or C- shaped cut-out portion orprotruded portion. This construction facilitates the handling of thelaminated core 20. Additionally, the fixing portion 219 is capable ofimproving the accuracy of positioning when the laminated core composedof a plurality of connecting stator cores is wound with wire.

FIG. 90 shows the stator 1 in which the laminated core 20 is bent at thethin portions 10 after the coils are formed (the representation of thecoils 2 is omitted here). In the stator 1, the protrusions facing eachother which acts as the magnetic path forming portion 314 of theneighboring stator components 9 of the laminated core 20 are fit to eachother or placed near each other and then the corresponding magnetic pathforming portions are fused and fixed through both end faces or a singleend face along the direction of the layers by means of YAG laser or thelike. In the same Figure, reference numeral 324 designates the weldedportion. FIG. 91 is a partial sectional view showing the detail of thewelded portion 324. By fusing and fixing the magnetic path formingportions 314 in this manner, the stator components 9 of the laminatedcore 20 can be fixed more firmly. That is, the integrated structure ofthe laminated core 20 is stabilized, so that mounting of the laminatedcore 20 onto the substrate through mainly the magnetic path formingportions 314 can be made firm and secure.

FIG. 92 shows the state in which a plurality of stacked magneticmaterials 321 are welded by spot welding a single position or aplurality of positions. That is, the magnetic materials 321 are nippedby the upper electrode 325 and the lower electrode 326 of the spotwelding machine along the thickness of the magnetic materials, pressureis applied to a plurality of stacked magnetic materials 321, and a largecurrent is supplied thereto in order to fix a plurality of the stackedmagnetic materials 321 by fusing the current passing portion by selfgenerated heat. As a result, a plurality of the stacked magneticmaterials 321 are fixed integratedly. In this case, the strength of spotwelding is larger than in the case of caulking or adhesion and further,it is possible to select the position to be spot-welded freely.

FIGS. 93, 94 show another method for fixing the magnetic materials. Asshown in FIG. 93, the protrusions 311 at a single position or aplurality of positions of the stacked magnetic materials 321 punched bymeans of press are nipped between the upper electrode 325 and the lowerelectrode 326 along the thickness thereof as shown in FIG. 94, pressureis applied to the stacked magnetic materials 321 and a large current issupplied to the stacked magnetic materials 321 in order to fuse thecurrent passing portion thereof. Consequently, a plurality of thestacked magnetic materials 321 are fixed integratedly. FIG. 95 is aschematic view of the fused portion 327 of the laminated core 20according to this method.

FIGS. 96, 97, 98 show still another method for fixing the magneticmaterials 321. As shown in FIG. 96, slight dent/protruding portions 328are provided at a position or a plurality of positions on the surface ofthe magnetic material 321. This dent/protruding portion 328 can beformed easily by pressing. Then, as shown in FIG. 97, a plurality of themagnetic materials 321 obtained by punching by press, the magneticmaterials having the dent/protruding portions 328, are stacked. Then,the locations corresponding to the dent/protruding portions 328 arenipped across the laminated core 20 by means of the upper electrode 325and the lower electrode 326 along the thickness of the laminated core20, pressure is applied to the laminated core and a large current issupplied thereto.

As a result, the dent/protruding portions 328 are locally heated by thelarge current passing therethrough and the dent/protruding portions 328are fused to each other at the fusing portions 327 as shown in FIG. 98,so that a plurality of the stacked magnetic materials 321 areintegratedly fixed.

FIG. 99 is a view showing the details of the coil forming portions ofthe magnetic pole teeth 15 in the laminated core 20. In this Figure,reference numeral 329 designates the cross section of the coil formingportion indicating the cut section. For example, as shown in FIG. 100,part or all of the corners in the cross section of the magneticmaterials 321 punched by means of press are formed so as to be ofsmoothly round shape 330. A plurality of such magnetic materials arestacked.

Then, it is possible to wind directly the laminated core 20 with wire orthe laminated core 20 covered with thin coating film with wire. That is,it is not necessary to perform insulation treatments on the laminatedcore 20, such as integrated molding of resin, formation of resin bobbinor fusing of insulating sheet.

FIGS. 101, 102 show the coil forming portion cross section 329 of otherconfiguration. The magnetic materials 321 punched by means of press havesuch cross section in which part or all of the corners are formed withlarge-radius round shape 331 and small-radius round shape 332.Large-radius round shapes 331 are formed on the outside edges of twooutermost pieces of stacked magnetic materials 321.

As a result, it is possible to wind directly the laminated core 20 withwire or the laminated core covered with thin coating film with wire.Additionally, this construction is capable of preventing wire from beingdamaged by the corners of the magnetic materials, located on both sidesof the laminated core. For example, if a round shape larger than half ofthe sheet thickness of the magnetic material is formed on the outeredges of the outermost two pieces, this construction can be also appliedto thin magnetic materials.

FIGS. 103, 104 are a partial perspective view and a partial sectionalview, respectively, showing the laminated core 20 of anotherconfiguration. FIG. 103 shows the state in which insulating thin plates333 are bonded to the upper and lower surfaces of the laminated core 20corresponding to the stator component 9. FIG. 104 shows the state of thecoil forming portion cross section 329, in which the insulating thinplates 333 are bonded to the upper and lower surfaces of the laminatedcore 20.

Consequently, this construction makes it possible to wind the laminatedcore 20 with wire without performing insulation treatment on thelaminated core 20, such integrated molding of resin, formation of resinbobbin and fusing of insulating sheet.

FIG. 105 is a partial perspective view of still another laminated core20 and FIG. 106 is a partial sectional view thereof. As shown in FIG.105, the laminated core contains film like wiring sheet 334 which issandwiched between arbitrary pieces of a plurality of the magneticmaterials 321 punched by means of press. The wiring sheet 334 has wiringpattern 335 which is arranged in the insulating sheet. FIG. 106 showsthe coil forming cross section 329 which contains the wiring sheet 334.

By forming the laminated core 20 in this manner, it is possible toconnect the terminal wire of the coil 2 to the wiring pattern 335 of thewiring sheet 334.

FIG. 107 is a partial perspective view of a further laminated core 20and FIG. 108 is a partial sectional view thereof. As shown in FIG. 107,the magnetic material substrate 336 is attached to one side of thelaminated core 20. The magnetic material substrate 336 is of the sameshape as the magnetic material 321, and insulating thin film andconductive thin film made of copper or the like are formed on thesurface thereof. The wiring pattern 335 is formed by etching theconductive thin film. FIG. 108 shows the coil forming cross section inwhich the magnetic material substrate 336 is formed on the top surfaceof the laminated core 20.

By forming the laminated core 20 in the aforementioned manner, it ispossible to connect directly the terminal wire of the coil 2 to themagnetic material substrate 336, thereby achieving thin structurelaminated core 20.

Embodiment 41

FIGS. 109-114 are explanatory views showing other method for forming thelaminated core 20. As shown in FIG. 110, the sheet-like magneticmaterial 321 having the teeth 15 arranged symmetrically with respect tothe axis line L is formed by punching by means of press. Then, as shownin FIG. 109, the magnetic material 321 is bent at a position (or aplurality of positions) in order to form the connecting stator core asshown in FIG. 111. This method makes it possible to position the burrportion on the edge of the magnetic material 321 formed due to punching,on the overlapping side and then position the drooping side on theoutside. That is, it is possible to provide the corner of the coilforming portion with roundness, thereby reducing damage of the coil.Further, a plurality of the magnetic materials 321 or the connectingstator cores are stacked as shown in FIG. 112 to form the laminated core20. Meanwhile, it is permissible to form the core 20 with only a singlemagnetic material 321.

Further, it is permissible to bend both sides of the magnetic pole teeth15 of the magnetic material 321 punched by means of press so that theedges of the bent portions contact each other in order to provide bothside ends with roundness and stack such magnetic pole teeth 15 to formthe laminated core 20 as shown in FIG. 114. In this manner, it ispossible to provide the corners of the cross section of the coil formingportion of the laminated core 20 with roundness, so that the burr formedby punching by press is not located on the corner of the cross sectionof the coil forming portion. As a result, it is possible to form thecoil 2 directly on the surface of the laminated core 20 or the laminatedcore coated with thin film.

Embodiment 42

FIG. 115 is a plan view of the laminated core 20 for AC servo motoraccording to the forty seventh embodiment of the present invention. ThisAC servo motor is a small sized, high power brushless motor used forautomation equipment, industrial robot or the like. FIG. 125 shows asectional view of the AC servo motor. In FIG. 125, reference numeral 1designates a stator, numeral 2 designates a coil, numeral 3 designates arotor and numeral 4 designates a rotor magnet.

In the present embodiment, the magnetic material punched by means ofpress is formed so that a plurality of the stator components 9 areconnected linearly by the thin portions 10, as shown in FIG. 115. Forexample, it is permissible to arrange a series of reinforcing material309 so that they bridge the thin portions 10 as shown in FIG. 116, thereinforcing material being separable from the stator components 9.

FIG. 117 shows an example in which resin is integratedly molded so as toform the coil forming portion 322 of the stator component 9, the neutralpoint treatment portion 338 and the connector portion 339 atpredetermined positions of the laminated core 20. Meanwhile, it ispermissible to construct the laminated core 20 so that the magneticmaterials 321 in which the thin portion 10 is formed are stacked withthe magnetic materials 321 in which the thin portion 10 is not formed.

As the method for fixing the laminated core 20, as shown in FIG. 92, itis possible to use such a method in which a large current is supplied toa position or a plurality of positions of the stacked magnetic materials321 with pressure applied to the stacked magnetic materials 321 in orderto fuse the current passing portions of the magnetic materials 321 byself generated heat. Or as shown in FIGS. 96-98, it is also possible touse such a method in which slight dent/protruding portions 328 areformed at a position or a plurality of positions on the surface of themagnetic material 321 punched by means of press, a plurality of thepunched magnetic materials 321 are stacked, the dent/protruding portions328 are nipped between the upper electrode 325 and the lower electrode326 along the thickness thereof and a large current is supplied withpressure applied to the stacked magnetic materials.

FIG. 118 shows the state in which the coils 2 are formed by winding wireintroduced from the wire nozzle 316 of the wire winding machine 317 asshown in FIGS. 119 and 124. In this wire winding process, the wirenozzle 316 is rotated around the magnetic pole tooth 15 and then theposition of the wire nozzle 316 is changed with respect to the laminatedcore 20, thereby facilitating to obtain the shape of coil in which wiresare neatly arranged. FIG. 124 shows the laminated core 20 is attached tothe index jig 340 during winding.

FIG. 120 shows the state in which the stator 1 is being formed bybending the laminated core 20 as shown in FIG. 118 through the thinportion 10. FIG. 121 shows the state in which the stator 1 has beenformed by bending all the thin portions 10 completely. In this Figure,reference numeral 3 designates a rotor. When the laminated core 20 hasbeen bent completely, as shown in FIG. 90, the neighboring magnetic pathforming portions 314 of the core portion 9 of the laminated core 20 arefit to each other or brought near each other, both ends or a single endthereof along the thickness of the laminated core 20 is fused and fixedby means of YAG laser or the like, thereby fixing together the coreportions 9 of the laminated core 2 firmly.

FIG. 122 shows the state in which the thin portions 10 protrude in theshape of arc as the thin pieces 10 c. FIG. 123 shows the state in whichthe respective thin portions 10 are thin arc pieces 10 d having no edge.

Embodiment 43

FIG. 126 is a plan view showing the laminated core 20 of an armaturemotor according to the forty third embodiment of the present invention.This armature motor is a small sized, high speed rotation, brushprovided motor used in electric fans of cleaners, electric drill and thelike. FIG. 134 shows a side view of an electric fan among those. In thisFigure, reference numeral designates a stator, numeral 2 designates acoil, numeral 3 designates a rotor and numeral 343 designates a bracket.

As shown in FIG. 126, the magnetic material 321 punched by means ofpress includes two stator components 9, two yoke portions 344 and thethin portions 10 which combine the stator components with the yokeportions, the respective members being connected to each other inseries. The laminated core 20 composed of the magnetic materials 321 maybe constructed so that the magnetic materials having the thin portion 10are stacked with the magnetic materials having no thin portion as shownin FIG. 88.

As the method for fixing the laminated core 20, it is possible to usesuch a method in which, as shown in FIG. 92, a large current is suppliedto a position or a plurality of positions of the stacked magneticmaterials 321 with pressure applied thereto and the current passingportions of the stacked magnetic materials 321 are fused by selfgenerated heat. Or it is also possible to use such a method in which, asshown in FIGS. 96-98, slight dent/protruding portions 328 are providedon a position or a plurality of positions on the surface of the magneticmaterials 321 punched by means of press, a plurality of the magneticmaterials 321 punched by press are stacked and the dent/protrudingportions 328 are nipped between the upper electrode 325 and the lowerelectrode 326 along the thickness of the stacked magnetic materials tosupply a large current thereto.

FIG. 127 shows the state in which the coils 2 are formed around themagnetic pole teeth 15 of the laminated core 20 and FIG. 128 shows theprocess in which the coils 2 are being formed. According to the methodshown in FIG. 128, the wire nozzle 316 for feeding wire are rotatedaround the magnetic pole teeth 15 and the position of the wire nozzle316 is changed with respect to the position of the laminated core 20.Consequently, it is possible to obtain the coils 2 arranged neatly.

FIG. 129 shows the process in which the stator 1 is being formed bybending the thin portions 10 of the laminated core 20 in which the coils2 are formed on the magnetic pole teeth 15. FIG. 130 shows the state inwhich all the thin portions 10 have been bent to form the stator 1. Whenall the thin portions 10 are bent completely, the magnetic path formingportions 314 of the neighboring core portion 9 of the laminated core 20are fit to each other or placed near each other as shown in FIG. 90 andboth end faces or a single end face of the laminated core 20 is fusedtogether by means of YAG laser or the like. As a result, the coreportions 9 of the laminated core 20 are fixed together firmly.

By pressing the stator 1 into the ring like bracket 343 after all thethin portions 10 are bent completely as shown in FIG. 131, it ispossible to fix the laminated core firmly.

In this case, in the process in which the thin portions are bent asshown in FIG. 132, the rotor 3 is disposed. Then, as shown in FIG. 133,all the thin portions 10 are bent to form the stator. After all the thinportions 10 are bent completely, the stator 1 is pressed into thebracket 343. According to this method, it is easy to wind wire so thatthe coils 2 are formed so as to surround the rotor 3.

Embodiment 44

FIG. 135 is a front view of the laminated core 20 for small sizetransformers. -As shown in the Figure, the yoke portion 344 which ispart of the magnetic path of the laminated core 20 is connected to asubstantially U-shaped core 9 through the thin portion 10. After a coilis mounted, the yoke portion 344 can be bent so as to close the U-shapedopening. As a method for fixing the laminated core, it is possible touse a conventional trimmed caulking portion. Further, it is possible touse such a method in which, as shown in FIG. 92, pressure is applied toa position or a plurality of positions of the stacked magnetic materialsby means of the upper electrode 325 and the lower electrode 326 and thena large current is supplied to fuse the current passing portion of thestacked magnetic materials 321 by self generated heat. Still further, itis possible to use such a method in which, as shown in FIGS. 96-98,slight dent/protruding portions 328 are provided at a position or aplurality of positions on the surface of the magnetic material 321punched by press, a plurality of the punched magnetic materials 321 arestacked, the dent/protruding portions 328 are nipped by the upperelectrode 325 and the lower electrode 326 along the thickness of thestacked magnetic materials to apply pressure and then a large current issupplied thereto.

As shown in FIGS. 136, 137, the coil 2 is formed on the bobbin 345 madeof insulating material, the bobbin is mounted around the leg of thelaminated core 20, and the yoke portion 344 is closed by bending thethin portion 10. As a result, as shown in FIG. 138, a magnetic path ofthe laminated core 20 is formed. With this condition, as shown in FIG.90, the neighboring magnetic path forming portions 314 of the laminatedcore 20 are fit to each other and then both end faces or a single endface along the stacked layers is fused in order to fix the cores 9 ofthe laminated core 20 firmly.

What is claimed is:
 1. A rotary motor comprising: a stator formed bybending a ribbon core, the core having a plurality of teeth; coilsformed by winding the plurality of teeth with wire, said coils connectedby a crossover wire connecting between said teeth of said stator; arotor located opposite said plurality of teeth of said stator portion;tying protrusions on which the beginning end or the terminating end ofthe wire is tied, the tying protrusions being formed on the stator,wherein the beginning end and the terminating end are tied on differenttying protrusions and each tying protrusion is used as a common terminalor a coil terminal.
 2. The rotary motor according to claim 1, whereinthe tying protrusions are formed on both ends of the ribbon core,wherein the tying protrusion formed on one end is used as the commonterminal and the tying protrusion formed on the other end is used as thecoil terminal.